#include #include #include "pico/stdlib.h" #include "pico/binary_info.h" #include "hardware/spi.h" #include #include "hardware/clocks.h" #include "hardware/dma.h" #include "blink.pio.h" #include "FastDAC.pio.h" #include "SlowDAC.pio.h" ///////////////////////////// // Define GPIO connections... ///////////////////////////// // Note: The SPI Port only works through specific pins, so this port is defined first. // SPI Port connections... // ┌──────────┬───────────────┬─────────────┐──────────────┐ // │ PGA2040 │ Connection │ MCP41010 │ Nixie module │ // ├──────────┼───────────────┼─────────────┤──────────────┤ #define PIN_RX 16 // │ GPIO 16 │ RX/spi1_rx │ │ - │ //#define PIN_CS 17 // │ GPIO 17 │ CS/spi1_cs │ │ │ can this be re-defined ? #define PIN_CLK 18 // │ GPIO 18 │ CLK/spi1_clk │ │ SCK (blue) │ #define PIN_TX 19 // │ GPIO 19 │ TX/spi1_tx │ │ SDI (green) │ #define Nixie_CS 21 // │ GPIO 21 │ Chip select │ │ SS1 (white) │ // └──────────┴───────────────┴─────────────┘──────────────┘ #define SPI_PORT spi0 // These SPI connections require the use of RP2040 SPI port 0 #define _A 0 // DAC channel alias #define _B 1 #define LED 20 // GPIO connected to LED #define BitMapSize 256 // Match X to Y resolution //#define BitMapSize 360 // won't work - DMA needs to operate as a power of 2 #define Slow 0 #define Fast 1 #define _Sine_ 0 // Permited values for variable WaveForm_Type #define _Square_ 1 #define _Triangle_ 2 #define _GPIO_ 0 #define _PIO_ 1 #define _BM_start_ 2 #define _SM_fast_ 3 #define _SM_slow_ 4 #define _SM_code_fast_ 5 #define _SM_code_slow_ 6 #define _SM_ 7 #define _DMA_ctrl_fast_ 8 #define _DMA_ctrl_slow_ 9 #define _DMA_data_fast_ 10 #define _DMA_data_slow_ 11 #define _Funct_ 12 #define _Phase_ 13 #define _Freq_ 14 #define _Range_ 15 #define _DutyC_ 16 unsigned short DAC_channel_mask = 0 ; // Binary mask to simultaneously start all DMA channels const uint32_t transfer_count = BitMapSize ; // Number of DMA transfers per event int WaveForm_Type; const uint startLineLength = 8; // the linebuffer will automatically grow for longer lines const char eof = 255; // EOF in stdio.h -is -1, but getchar returns int 255 to avoid blocking int ParmCnt = 0, Parm[4] ; // Storage for 4 command line parameters int SelectedChan, c, i = 0, dirn = 1 ; const char * HelpText = "\tUsage...\n" "\t ? - Usage\n" "\t S - Status\n" "\t I - System info\n" "\t fnnn - Frequency ( 0->999 )\n" "\t h - Frequency multiplier Hz\n" "\t k - Frequency multiplier KHz\n" "\t snnn - Sine wave + harmonic ( 0->9 )\n" "\t qnnn - Square wave + duty cycle ( 0->100%% )\n" "\t tnnn - Triangle wave + duty cycle ( 0->100%% )\n" "\t pnnn - Phase ( 0->360 degrees )\n" "\t w - Sweep frequency\n" "\t - DAC channel A,B or Both\n" "\t nnn - Three digit numeric value\n"; class DACchannel { // static void pio_sm_set_wrap ( PIO pio, uint sm, uint wrap_target, uint wrap ) unsigned short DAC_data[BitMapSize] __attribute__ ((aligned(2048))) ; // Align DAC data (2048d = 0800h) uint StateMachine[2] ; // Fast and slow State Machines uint Funct, Phase, Freq, Range, DutyC; uint GPIO, _pioNum, SM_fast, SM_slow, SM_code_fast ; // Variabes used by the getter function... uint SM_code_slow, ctrl_chan_fast, ctrl_chan_slow ; uint data_chan_fast, data_chan_slow ; PIO pio; // Class wide var to share value with setter function public: // Setter functions... void ReInit () { // Re-initialises DMA channels to their initial state. // Note: 1) DMA channels are not restarted, allowing an atomic (simultaneous) restart of both DAC channels later. // 2) Cannot use dma_hw->abort on chained DMA channels, so using disable and re-enable instead. // 3) This needs to be performed across both DAC channels to ensure phase sync is maintained. // Disable all 4 DMA channels associated with this DAC... hw_clear_bits(&dma_hw->ch[data_chan_fast].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); hw_clear_bits(&dma_hw->ch[data_chan_slow].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); hw_clear_bits(&dma_hw->ch[ctrl_chan_fast].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); hw_clear_bits(&dma_hw->ch[ctrl_chan_slow].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); // Reset the data transfer DMA's to the start of the data Bitmap... dma_channel_set_read_addr(data_chan_fast, &DAC_data[0], false); dma_channel_set_read_addr(data_chan_slow, &DAC_data[0], false); // Re-enable all 4 DMA channels associated with this DAC... hw_set_bits(&dma_hw->ch[data_chan_fast].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); hw_set_bits(&dma_hw->ch[data_chan_slow].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); hw_set_bits(&dma_hw->ch[ctrl_chan_fast].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); hw_set_bits(&dma_hw->ch[ctrl_chan_slow].al1_ctrl, DMA_CH0_CTRL_TRIG_EN_BITS); } void SetFunct (int _value) { Funct = _value; } // Function (Sine/Triangl/Square) void SetDutyC (int _value) { DutyC = _value; } // Duty cycle (0->100%) void SetRange (int _value) { Range = _value; // Range (Hz/KHz) DACspeed(Freq * Range); } // Update State MAchine run speed void SetFreq (int _value) { Freq = _value; // Frequency (numeric) DACspeed(Freq * Range); } // Update State machine run speed void SetPhase (int _value) { Phase = _value; // Phase shift (0->360 degrees) DACspeed(Freq * Range); } void DACspeed (int _frequency) { // If DAC_div exceeds 2^16 (65,536), the registers wrap around, and the State Machine clock will be incorrect. // A slow version of the DAC State Machine is used for frequencies below 17Hz, allowing the value of DAC_div to // be kept within range. float DAC_freq = _frequency * BitMapSize; // Target frequency... float DAC_div = 2 * (float)clock_get_hz(clk_sys) / DAC_freq; // ...calculate the PIO clock divider required for the given Target frequency float Fout = 2 * (float)clock_get_hz(clk_sys) / (BitMapSize * DAC_div); // Actual output frequency if (_frequency >= 34) { // Fast DAC ( Frequency range from 34Hz to 999Khz ) pio_sm_set_clkdiv(pio, StateMachine[Fast], DAC_div); // Set the State Machine clock speed pio_sm_set_enabled(pio, StateMachine[Fast], true); // Fast State Machine active pio_sm_set_enabled(pio, StateMachine[Slow], false); // Slow State Machine inactive } else { // Slow DAC ( 1Hz=>16Hz ) DAC_div = DAC_div / 64; // Adjust DAC_div to keep within useable range DAC_freq = DAC_freq * 64; pio_sm_set_clkdiv(pio, StateMachine[Slow], DAC_div); // Set the State Machine clock speed pio_sm_set_enabled(pio, StateMachine[Fast], false); // Fast State Machine inactive pio_sm_set_enabled(pio, StateMachine[Slow], true); // Slow State Machine active } } void DataCalc () { // int i,h_index, v_offset = BitMapSize/2 - 1; // Shift sine waves up above X axis int i,j, v_offset = 256/2 - 1; // Shift sine waves up above X axis int _phase; const float _2Pi = 6.283; // 2*Pi float a,b,x1,x2,g1,g2; // Scale the phase shift to match data size... _phase = Phase * BitMapSize / 360 ; // Input range: 0 -> 360 (degrees) // Output range: 0 -> 255 (bytes) switch (Funct) { case _Sine_: DutyC = DutyC % 10; // Sine value cycles after 7 for (i=0; i= 1) { a += v_offset/3 * sin((float)_2Pi*3*i / (float)BitMapSize); } // Add 3rd harmonic if (DutyC >= 2) { a += v_offset/5 * sin((float)_2Pi*5*i / (float)BitMapSize); } // Add 5th harmonic if (DutyC >= 3) { a += v_offset/7 * sin((float)_2Pi*7*i / (float)BitMapSize); } // Add 7th harmonic if (DutyC >= 4) { a += v_offset/9 * sin((float)_2Pi*9*i / (float)BitMapSize); } // Add 9th harmonic if (DutyC >= 5) { a += v_offset/11 * sin((float)_2Pi*11*i / (float)BitMapSize); } // Add 11th harmonic if (DutyC >= 6) { a += v_offset/13 * sin((float)_2Pi*13*i / (float)BitMapSize); } // Add 13th harmonic if (DutyC >= 7) { a += v_offset/15 * sin((float)_2Pi*15*i / (float)BitMapSize); } // Add 15th harmonic if (DutyC >= 8) { a += v_offset/17 * sin((float)_2Pi*17*i / (float)BitMapSize); } // Add 17th harmonic if (DutyC >= 9) { a += v_offset/19 * sin((float)_2Pi*19*i / (float)BitMapSize); } // Add 19th harmonic DAC_data[j] = (int)(a)+v_offset; // Sum all harmonics and add vertical offset } break; case _Square_: b = DutyC * BitMapSize / 100; // Convert % to value for (i=0; i x1) { DAC_data[j] = (BitMapSize - 1) - ((i - x1) * g2); } // Falling section of waveform } } } // Getter functions... int Get_Resource (int _index) { int result; switch (_index) { case _GPIO_: result = GPIO; break; case _PIO_: result = _pioNum; break; case _BM_start_: result = (int)&DAC_data[0]; break; case _SM_fast_: result = SM_fast; break; case _SM_slow_: result = SM_slow; break; case _SM_code_fast_ : result = SM_code_fast; break; case _SM_code_slow_ : result = SM_code_slow; break; case _DMA_ctrl_fast_: result = ctrl_chan_fast; break; case _DMA_ctrl_slow_: result = ctrl_chan_slow; break; case _DMA_data_fast_: result = data_chan_fast; break; case _DMA_data_slow_: result = data_chan_slow; break; case _Funct_: result = Funct; break; case _Phase_: result = Phase; break; case _Freq_: result = Freq; break; case _Range_: result = Range; break; case _DutyC_: result = DutyC; break; } return (result); } public: // Constructor // Parameters... // _pio = the required PIO channel // _GPIO = the port connecting to the MSB of the R-2-R resistor network. // The PIO clock dividers are 16-bit integer, 8-bit fractional, with first-order delta-sigma for the fractional divider. // The clock divisor can vary between 1 and 65536, in increments of 1/256. // If DAC_div exceeds 2^16 (65,536), the registers wrap around, and the State Machine clock will be incorrect. // A slow version of the DAC State Machine is used for frequencies below 17Hz, allowing the value of DAC_div to // be kept within range. void NewDMAtoDAC_channel(PIO _pio, uint _GPIO) { pio = _pio, GPIO = _GPIO; // copy parameters to class vars _pioNum = pio_get_index(_pio); StateMachine[Fast] = Single_DMA_FIFO_SM_GPIO_DAC(_pio,Fast,_GPIO); // Create the Fast DAC channel (frequencies: 17Hz to 999KHz) StateMachine[Slow] = Single_DMA_FIFO_SM_GPIO_DAC(_pio,Slow,_GPIO); // Create the Slow DAC channel (frequencies: 0Hz to 16Hz) }; public: int Single_DMA_FIFO_SM_GPIO_DAC(PIO _pio, int _speed, uint _startpin) { // Create a DMA channel and its associated State Machine. // DMA => FIFO => State Machine => GPIO pins => DAC uint _pioNum = pio_get_index(_pio); // Get user friendly index number. int _offset; uint _StateMachine = pio_claim_unused_sm(_pio, true); // Find a free state machine on the specified PIO - error if there are none. uint ctrl_chan = dma_claim_unused_channel(true); // Find 2 x free DMA channels for the DAC (12 available) uint data_chan = dma_claim_unused_channel(true); if (_speed == 1) { // Configure the state machine to run the FastDAC program... SM_fast = _StateMachine; _offset = pio_add_program(_pio, &pio_FastDAC_program); SM_code_fast = _offset; pio_FastDAC_program_init(_pio, _StateMachine, _offset, _startpin); ctrl_chan_fast = ctrl_chan ; // Make details available to getter functions data_chan_fast = data_chan ; } else { // Configure the state machine to run the SlowDAC program... SM_slow = _StateMachine; _offset = pio_add_program(_pio, &pio_SlowDAC_program); // Use helper function included in the .pio file. SM_code_slow = _offset; pio_SlowDAC_program_init(_pio, _StateMachine, _offset, _startpin); ctrl_chan_slow = ctrl_chan ; // Make details available to getter functions data_chan_slow = data_chan ; } // Setup the DAC control channel... // The control channel transfers two words into the data channel's control registers, then halts. The write address wraps on a two-word // (eight-byte) boundary, so that the control channel writes the same two registers when it is next triggered. dma_channel_config fc = dma_channel_get_default_config(ctrl_chan); // default configs channel_config_set_transfer_data_size(&fc, DMA_SIZE_32); // 32-bit txfers channel_config_set_read_increment(&fc, false); // no read incrementing channel_config_set_write_increment(&fc, false); // no write incrementing dma_channel_configure( ctrl_chan, &fc, &dma_hw->ch[data_chan].al1_transfer_count_trig, // txfer to transfer count trigger &transfer_count, 1, false ); // Setup the DAC data channel... // 32 bit transfers. Read address increments after each transfer. fc = dma_channel_get_default_config(data_chan); channel_config_set_transfer_data_size(&fc, DMA_SIZE_32); // 32-bit txfers channel_config_set_read_increment(&fc, true); // increment the read adddress channel_config_set_write_increment(&fc, false); // don't increment write address channel_config_set_dreq(&fc, pio_get_dreq(_pio, _StateMachine, true)); // Transfer when PIO SM TX FIFO has space channel_config_set_chain_to(&fc, ctrl_chan); // chain to the controller DMA channel channel_config_set_ring(&fc, false, 9); // 8 bit DAC 1<<9 byte boundary on read ptr. This is why we needed alignment! dma_channel_configure( data_chan, // Channel to be configured &fc, // The configuration we just created &_pio->txf[_StateMachine], // Write to FIFO DAC_data, // The initial read address (AT NATURAL ALIGNMENT POINT) BitMapSize, // Number of transfers; in this case each is 2 byte. false // Don't start immediately. All 4 control channels need to start simultaneously // to ensure the correct phase shift is applied. ); // Note: All DMA channels are left running permanently. The active channel is selected by enabling/disabling the associated State Machine. DAC_channel_mask += (1u << ctrl_chan) ; // Save details of DMA control channel to global variable return(_StateMachine); } }; class blink_forever { // Class to initialise a state machine to blink a GPIO pin PIO pio ; // Class wide variables to share value with setter function uint pioNum, StateMachine, Freq, _offset ; public: blink_forever(PIO _pio) { pio = _pio; // transfer parameter to class wide var pioNum = pio_get_index(_pio); StateMachine = pio_claim_unused_sm(_pio, true); // Find a free state machine on the specified PIO - error if there are none. _offset = pio_add_program(_pio, &pio_blink_program); blink_program_init(_pio, StateMachine, _offset, LED ); pio_sm_set_enabled(_pio, StateMachine, true); } // Setter function... void Set_Frequency(int _frequency){ Freq = _frequency; // Copy parm to class var // Frequency scaled by 2000 as blink.pio requires this number of cycles to complete... float DAC_div = (float)clock_get_hz(clk_sys) /((float)_frequency*2000); pio_sm_set_clkdiv(pio, StateMachine, DAC_div); // Set the State Machine clock speed } // Getter function... int Get_Resource (int _index) { int result; switch (_index) { case _GPIO_: result = LED; break; case _SM_: result = StateMachine; break; case _PIO_: result = pioNum; break; case _Freq_: result = Freq; break; } return (result); } }; void ChanInfo ( DACchannel DACchannel[], int _chanNum) { // Print current channel parameters to the console... char Chan, WaveStr[9], MultStr[4]; int value = DACchannel[_chanNum].Get_Resource(_Funct_); int test = DACchannel[_chanNum].Get_Resource(_Phase_); switch ( value ) { case _Sine_: strcpy(WaveStr, "Sine"); break; case _Triangle_: strcpy(WaveStr, "Triangle"); break; case _Square_: strcpy(WaveStr,"Square"); } _chanNum == 0 ? Chan = 'A' : Chan = 'B'; DACchannel[_chanNum].Get_Resource(_Range_) == 1 ? strcpy(MultStr,"Hz ") : strcpy(MultStr,"KHz"); printf("\tChannel %c: Freq:%03d%s Phase:%03d Wave:%s\n", Chan, DACchannel[_chanNum].Get_Resource(_Freq_), MultStr, DACchannel[_chanNum].Get_Resource(_Phase_), WaveStr); } void SysInfo ( DACchannel DACchannel[], blink_forever LED_blinky) { // Print system and resource allocation details... int a,b,c,d ; a = LED_blinky.Get_Resource(_PIO_); b = LED_blinky.Get_Resource(_SM_); c = LED_blinky.Get_Resource(_GPIO_); d = LED_blinky.Get_Resource(_Freq_); printf("\n|-----------------------------------------------------------|\n"); printf("| Waveform Generator Ver: 0.0.1 Date: 21/03/2013 |\n"); printf("|-----------------------------|-----------------------------|\n"); printf("| LED blinker | |\n"); printf("|-----------------------------| |\n"); printf("| PIO: %2d | Key: |\n",a); printf("| SM: %2d | SM = State machine |\n",b); printf("| GPIO: %2d | BM = Bitmap |\n",c); printf("| Frequency: %2dHz | |\n",d); printf("|-----------------------------|-----------------------------|\n"); printf("| DAC channel A | DAC channel B |\n"); printf("|-----------------------------|-----------------------------|\n"); a = DACchannel[_A].Get_Resource(_PIO_); b = DACchannel[_B].Get_Resource(_PIO_); printf("| PIO: %d | PIO: %d |\n",a,b); a = DACchannel[_A].Get_Resource(_GPIO_); b = DACchannel[_B].Get_Resource(_GPIO_); printf("| GPIO: %d-%d | GPIO: %d-%d |\n",a,a+7,b,b+7); printf("| BM size: %8d | BM size: %8d |\n", BitMapSize, BitMapSize); a = DACchannel[_A].Get_Resource(_BM_start_); b = DACchannel[_B].Get_Resource(_BM_start_); printf("| BM start: %x | BM start: %x |\n",a,b); printf("| Divider: %05x | Divider: %05x |\n",0,0); printf("|--------------|--------------|--------------|--------------|\n"); printf("| Fast DAC | Slow DAC | Fast DAC | Slow DAC |\n"); printf("|--------------|--------------|--------------|--------------|\n"); a = DACchannel[_A].Get_Resource(_SM_fast_); b = DACchannel[_A].Get_Resource(_SM_slow_); c = DACchannel[_B].Get_Resource(_SM_fast_); d = DACchannel[_B].Get_Resource(_SM_slow_); printf("| SM: %d | SM: %d | SM: %d | SM: %d |\n",a,b,c,d); a = DACchannel[_A].Get_Resource(_SM_code_fast_); b = DACchannel[_A].Get_Resource(_SM_code_slow_); c = DACchannel[_B].Get_Resource(_SM_code_fast_); d = DACchannel[_B].Get_Resource(_SM_code_slow_); printf("| SM code: %2d | SM code: %2d | SM code: %2d | SM code: %2d |\n",a,b,c,d); a = DACchannel[_A].Get_Resource(_DMA_ctrl_fast_); b = DACchannel[_A].Get_Resource(_DMA_ctrl_slow_); c = DACchannel[_B].Get_Resource(_DMA_ctrl_fast_); d = DACchannel[_B].Get_Resource(_DMA_ctrl_slow_); printf("| DMA ctrl: %2d | DMA ctrl: %2d | DMA ctrl: %2d | DMA ctrl: %2d |\n",a,b,c,d); a = DACchannel[_A].Get_Resource(_DMA_data_fast_); b = DACchannel[_A].Get_Resource(_DMA_data_slow_); c = DACchannel[_B].Get_Resource(_DMA_data_fast_); d = DACchannel[_B].Get_Resource(_DMA_data_slow_); printf("| DMA data: %2d | DMA data: %2d | DMA data: %2d | DMA data: %2d |\n",a,b,c,d); printf("|--------------|--------------|--------------|--------------|\n"); } static inline void cs_select() { asm volatile("nop \n nop \n nop"); gpio_put(Nixie_CS, 0); // Active low asm volatile("nop \n nop \n nop"); } static inline void cs_deselect() { asm volatile("nop \n nop \n nop"); gpio_put(Nixie_CS, 1); asm volatile("nop \n nop \n nop"); } static void SPI_Nixie_Write(int _data) { uint8_t buff[2]; buff[0] = _data / 256; // MSB data buff[1] = _data % 256; // LSB data cs_select(); spi_write_blocking(SPI_PORT, buff, 2); cs_deselect(); } static char * getLine(bool fullDuplex = false, char lineBreak = '\n') { /* * read a line of any length from stdio (grows) * * @param fullDuplex input will echo on entry (terminal mode) when false * @param linebreak defaults to "\n", but "\r" may be needed for terminals * @return entered line on heap - don't forget calling free() to get memory back */ // th line buffer // will allocated by pico_malloc module if gets included char * pStart = (char*)malloc(startLineLength); char * pPos = pStart; // next character position size_t maxLen = startLineLength; // current max buffer size size_t len = maxLen; // current max length int c; if(!pStart) { return NULL; // out of memory or dysfunctional heap } while(1) { c = getchar(); // expect next character entry if(c == eof || c == lineBreak) { break; // non blocking exit } if (fullDuplex) { putchar(c); // echo for fullDuplex terminals } if(--len == 0) { // allow larger buffer len = maxLen; // double the current line buffer size char *pNew = (char*)realloc(pStart, maxLen *= 2); if(!pNew) { free(pStart); return NULL; // out of memory abort } // fix pointer for new buffer pPos = pNew + (pPos - pStart); pStart = pNew; } // stop reading if lineBreak character entered if((*pPos++ = c) == lineBreak) { break; } } *pPos = '\0'; // set string end mark return pStart; } int main() { stdio_init_all(); // Set SPI0 at 0.5MHz. spi_init(SPI_PORT, 500 * 1000); gpio_set_function(PIN_CLK, GPIO_FUNC_SPI); gpio_set_function(PIN_TX, GPIO_FUNC_SPI); // Chip select is active-low, so initialise to a driven-high state... gpio_init(Nixie_CS); gpio_set_dir(Nixie_CS, GPIO_OUT); gpio_put(Nixie_CS, 1); // Initialise remaining SPI connections... gpio_set_dir(PIN_CLK, GPIO_OUT); gpio_set_dir(PIN_TX, GPIO_OUT); DACchannel DACchannel[2]; // Array to hold the two DAC channel objects // Set up the objects controlling the various State Machines... // Note: Both DAC channels need to be on the same PIO to acheive accurate phase sync. DACchannel[_A].NewDMAtoDAC_channel(pio1,0); // First DAC channel object in array - resistor network connected to GPIO0->7 DACchannel[_B].NewDMAtoDAC_channel(pio1,8); // Second DAC channel object in array - resistor network connected to GPIO8->15 blink_forever LED_blinky(pio0); // Onboard LED blinky object // Set LED to slow flash indicates waiting for USB connection... LED_blinky.Set_Frequency(1); // 1Hz // Wait for USB connection... while (!stdio_usb_connected()) { sleep_ms(100); } // USB connection established, set LED to rapid flash... LED_blinky.Set_Frequency(10); // 10Hz SysInfo(DACchannel, LED_blinky); // Show configuration (optional) // printf(HelpText); // Show instructions (optional) // Set default run time settings... DACchannel[_A].SetFreq(100), DACchannel[_B].SetFreq(100) ; // 100 DACchannel[_A].SetRange(1), DACchannel[_B].SetRange(1) ; // Hz DACchannel[_A].SetPhase(0), DACchannel[_B].SetPhase(180) ; // 180 phase diff DACchannel[_A].SetFunct(_Sine_), DACchannel[_B].SetFunct(_Sine_) ; // Sine wave, no harmonics DACchannel[_A].SetDutyC(50), DACchannel[_B].SetDutyC(50); // 50% Duty cycle DACchannel[_A].DataCalc(), DACchannel[_B].DataCalc(); // Generate the two data sets SPI_Nixie_Write(DACchannel[_A].Get_Resource(_Freq_)); // Frequency => Nixie display // Starting all 4 DMA channels simultaneously ensures phase sync across all State Machines... dma_start_channel_mask(DAC_channel_mask); while(1) { char *inString = getLine(true, '\r') ; ParmCnt = 0, Parm[0]=0, Parm[1]=0, Parm[2]=0, Parm[3]=0; // Perform single character instructions... if (inString[0] == '?') { printf(HelpText); } // Help text if (inString[0] == 'S') { ChanInfo(DACchannel, _A); // Status info ChanInfo(DACchannel, _B); } if (inString[0] == 'I') { SysInfo(DACchannel, LED_blinky); } // Select DAC channel A or B... if (inString[0] == 'A') { SelectedChan = 0b0001; } // Channel A if (inString[0] == 'B') { SelectedChan = 0b0010; } // Channel B if (inString[0] == 'C') { SelectedChan = 0b0011; } // Channel A & B // Parse command line to extract numeric parameters. Leading zeros are ignored... i = 1 ; // Skip chars 0 & 1 while (i++ < strlen(inString)-1 ) { // Start at char 2 if ( inString[i] == ',' ) { ParmCnt++ ; } // Next parameter else { Parm[ParmCnt] *= 10; // Next digit. Bump the existing decimal digits Parm[ParmCnt] += inString[i] - '0'; } // Convert character to integer and add } // Perform the selected command... switch ( inString[1] ) { case 'w': // Frequency sweep i = Parm[0]; for (;;) { DACchannel[_A].ReInit(); // Stop DAC channel A and re-initialise DMA to start of Bitmap data DACchannel[_B].ReInit(); // Stop DAC channel B and re-initialise DMA to start of Bitmap data if (SelectedChan & 0b01) { DACchannel[_A].SetFreq(i); ChanInfo(DACchannel, _A); // Update the terminal } if (SelectedChan & 0b10) { DACchannel[_B].SetFreq(i); ChanInfo(DACchannel, _B); // Update the terminal } dma_start_channel_mask(DAC_channel_mask); // Atomically Restart all 4 DMA channels... SPI_Nixie_Write(i); // Update Nixie display if (i==Parm[0]) { dirn = 1; sleep_ms(Parm[3]); } // Count up from zero, pause at end if (i>=Parm[1]) { dirn =-1; sleep_ms(Parm[3]); } // Count down from 100, pause at start i = i + dirn; c = getchar_timeout_us (0); // Non-blocking char input if ((c>=32) & (c<=126)) { break; } // exit on keypress sleep_ms(Parm[2]); // Speed of scan } break; case 's': // Sine wave if (SelectedChan & 0b01) { DACchannel[_A].SetFunct(_Sine_); DACchannel[_A].SetDutyC(Parm[0]); DACchannel[_A].DataCalc(); } if (SelectedChan & 0b10) { DACchannel[_B].SetFunct(_Sine_); DACchannel[_B].SetDutyC(Parm[0]); DACchannel[_B].DataCalc(); } break; case 't': // Triangle wave if ( Parm[0] > 100 ) { Parm[0] = 100; } // Hard limit @ 100% if (SelectedChan & 0b01) { DACchannel[_A].SetFunct(_Triangle_); DACchannel[_A].SetDutyC(Parm[0]); DACchannel[_A].DataCalc(); } if (SelectedChan & 0b10) { DACchannel[_B].SetFunct(_Triangle_); DACchannel[_B].SetDutyC(Parm[0]); DACchannel[_B].DataCalc(); } break; case 'q': if ( Parm[0] > 100 ) { Parm[0] = 100; } // Hard limit @ 100% if (SelectedChan & 0b01) { DACchannel[_A].SetFunct(_Square_); DACchannel[_A].SetDutyC(Parm[0]); DACchannel[_A].DataCalc(); } if (SelectedChan & 0b10) { DACchannel[_B].SetFunct(_Square_); DACchannel[_B].SetDutyC(Parm[0]); DACchannel[_B].DataCalc(); } break; case 'h': // Set Hz if (SelectedChan & 0b01) { DACchannel[_A].SetRange(1); } if (SelectedChan & 0b10) { DACchannel[_B].SetRange(1); } break; case 'k': // Set KHz if (SelectedChan & 0b01) { DACchannel[_A].SetRange(1000); } if (SelectedChan & 0b10) { DACchannel[_B].SetRange(1000); } break; case 'f': DACchannel[_A].ReInit(); // Stop DAC channel A and re-initialise DMA to start of Bitmap data DACchannel[_B].ReInit(); // Stop DAC channel B and re-initialise DMA to start of Bitmap data // TBD: this may throw any existing phase setting out. // Recalc both channels ensures phase settings are preserved. if (SelectedChan & 0b01) { DACchannel[_A].SetFreq(Parm[0]); } if (SelectedChan & 0b10) { DACchannel[_B].SetFreq(Parm[0]); } dma_start_channel_mask(DAC_channel_mask); // Atomically Restart all 4 DMA channels break; case 'p': DACchannel[_A].ReInit(); // Stop DAC channel A and re-initialise DMA to start of Bitmap data DACchannel[_B].ReInit(); // Stop DAC channel B and re-initialise DMA to start of Bitmap data if (SelectedChan & 0b01) { DACchannel[_A].SetPhase(Parm[0]); // Update DAC phase. DACchannel[_A].DataCalc(); // Update Bitmap data to include new DAC phase } if (SelectedChan & 0b10) { DACchannel[_B].SetPhase(Parm[0]); // Update DAC phase. DACchannel[_B].DataCalc(); // Update Bitmap data to include new DAC phase } dma_start_channel_mask(DAC_channel_mask); // Atomically Restart all 4 DMA channels break; default: printf("\tUnknown command\n"); } if (SelectedChan & 0b01) { ChanInfo(DACchannel, _A); } // Update the terminal if (SelectedChan & 0b10) { ChanInfo(DACchannel, _B); } SPI_Nixie_Write(Parm[0]); // Update Nixie display free(inString); // free buffer } return 0; }