#include #include #include "pico/stdlib.h" #include "hardware/pio.h" #include "hardware/irq.h" #include "hardware/clocks.h" #include "hardware/dma.h" #include "rotary_encoder.pio.h" #include "blink.pio.h" #include "FastDAC.pio.h" #include "SlowDAC.pio.h" #define sine_table_size 256 // Number of samples per period in sine table #define SW_3way_1 14 // GPIO connection #define SW_3way_2 15 // GPIO connection // Global variables... int SW_3way; int LastFrequency, LastWaveForm, LastLevel, Last_SW_3way; int LastVal; int tmp; // DEBUG USE int ScanCtr, FlashCtr; int DAC[5] = { 2, 3, 4, 5, 6 }; // DAC ports - DAC0=>2 DAC4=>6 int NixieCathodes[4] = { 18, 19, 20, 21 }; // GPIO ports connecting to Nixie Cathodes - Data0=>18 Data3=>21 int NixieAnodes[3] = { 22, 26, 27 }; // GPIO ports connecting to Nixie Anodes - Anode0=>22 Anode2=>27 int EncoderPorts[2] = { 16, 17 }; // GPIO ports connecting to Rotary Encoder - 16=>Clock 17=>Data int NixieBuffer[3] = { 6, 7, 8 }; // Values to be displayed on Nixie tubes - Tube0=>1's // - Tube1=>10's // - Tube2=>100's int raw_sin[sine_table_size] ; unsigned short DAC_data[sine_table_size] __attribute__ ((aligned(2048))) ; // Align DAC data const uint32_t transfer_count = sine_table_size ; // Number of DMA transfers per event void blink_pin_forever(PIO pio, uint sm, uint offset, uint pin, uint freq); class RotaryEncoder { // class to initialise a state machine to read public: // the rotation of the rotary encoder // constructor // rotary_encoder_A is the pin for the A of the rotary encoder. // The B of the rotary encoder has to be connected to the next GPIO. RotaryEncoder(uint rotary_encoder_A, uint freq) { uint8_t rotary_encoder_B = rotary_encoder_A + 1; PIO pio = pio0; // Use pio 0 uint8_t sm = 1; // Use state machine 1 pio_gpio_init(pio, rotary_encoder_A); gpio_set_pulls(rotary_encoder_A, false, false); // configure the used pins as input without pull up pio_gpio_init(pio, rotary_encoder_B); gpio_set_pulls(rotary_encoder_B, false, false); // configure the used pins as input without pull up uint offset = pio_add_program(pio, &pio_rotary_encoder_program); // load the pio program into the pio memory... pio_sm_config c = pio_rotary_encoder_program_get_default_config(offset); // make a sm config... sm_config_set_in_pins(&c, rotary_encoder_A); // set the 'in' pins sm_config_set_in_shift(&c, false, false, 0); // set shift to left: bits shifted by 'in' enter at the least // significant bit (LSB), no autopush irq_set_exclusive_handler(PIO0_IRQ_0, pio_irq_handler); // set the IRQ handler irq_set_enabled(PIO0_IRQ_0, true); // enable the IRQ pio0_hw->inte0 = PIO_IRQ0_INTE_SM0_BITS | PIO_IRQ0_INTE_SM1_BITS; pio_sm_init(pio, sm, 16, &c); // init the state machine // Note: the program starts after the jump table -> initial_pc = 16 pio_sm_set_enabled(pio, sm, true); // enable the state machine printf("PIO:0 SM:%d - Rotary encoder' @ %dHz\n\n", sm, freq); } void set_Frequency(int _Frequency) { Frequency = _Frequency; } void set_WaveForm(int _WaveForm) { WaveForm = _WaveForm; } void set_Level(int _Level) { Level = _Level; } int get_Frequency(void) { return Frequency; } int get_WaveForm(void) { return WaveForm; } int get_Level(void) { return Level; } private: static void pio_irq_handler() { if (pio0_hw->irq & 2) { // test if irq 0 was raised switch (SW_3way) { case 0b010: // Top: Frequency range 0 to 999 Frequency--; if ( Frequency < 0 ) { Frequency = 999; } break; case 0b001: // Bottom : Level range 0 to 99 Level--; if ( Level < 0 ) { Level = 99; } break; case 0b011: // Middle: WaveForm range 0 to 4 WaveForm--; if ( WaveForm < 0 ) { WaveForm = 5; } } } if (pio0_hw->irq & 1) { // test if irq 1 was raised switch (SW_3way) { case 0b010: // Top: Frequency range 0 to 999 Frequency++; if ( Frequency > 999 ) { Frequency = 0; } break; case 0b001: // Bottom : Level range 0 to 99 Level++; if ( Level > 99 ) { Level = 0; } break; case 0b011: // Middle: WaveForm range 0 to 4 WaveForm++; if ( WaveForm > 5 ) { WaveForm = 0; } } } pio0_hw->irq = 3; // clear both interrupts } PIO pio; // the pio instance uint sm; // the state machine static int Frequency; static int WaveForm; static int Level; }; // Global Var... int RotaryEncoder::Frequency; // Initialize static members of class Rotary_encoder int RotaryEncoder::WaveForm; // Initialize static members of class Rotary_encoder int RotaryEncoder::Level; // Initialize static members of class Rotary_encoder class blink_forever { // Class to initialise a state macne to blink a GPIO pin public: blink_forever(PIO pio, uint sm, uint offset, uint pin, uint freq, uint blink_div) { blink_program_init(pio, sm, offset, pin, blink_div); pio_sm_set_enabled(pio, sm, true); printf("PIO:0 SM:%d - Blink @ %dHz\n", sm, freq); } }; void WriteCathodes (int Data) { // Create bit pattern on cathode GPIO's corresponding to the Data input... int shifted; shifted = Data ; gpio_put(NixieCathodes[0], shifted %2) ; shifted = shifted /2 ; gpio_put(NixieCathodes[1], shifted %2); shifted = shifted /2; gpio_put(NixieCathodes[2], shifted %2); shifted = shifted /2; gpio_put(NixieCathodes[3], shifted %2); } bool Repeating_Timer_Callback(struct repeating_timer *t) { // Scans the Nixie Anodes, and transfers data from the Nixie Buffers to the Cathodes. switch (ScanCtr) { case 0: gpio_put(NixieAnodes[2], 0) ; // Turn off previous anode WriteCathodes(NixieBuffer[0]); // Set up new data on cathodes (Units) gpio_put(NixieAnodes[0], 1) ; // Turn on current anode break; case 1: gpio_put(NixieAnodes[0], 0) ; // Turn off previous anode WriteCathodes(NixieBuffer[1]); // Set up new data on cathodes (10's) gpio_put(NixieAnodes[1], 1) ; // Turn on current anode break; case 2: gpio_put(NixieAnodes[1], 0) ; // Turn off previous anode WriteCathodes(NixieBuffer[2]); // Set up new data on cathodes (100's) gpio_put(NixieAnodes[2], 1) ; // Turn on current anode. } ScanCtr++; if ( ScanCtr > 2 ) { ScanCtr = 0; } // Bump and Wrap the counter return true; } int main() { int temp; static const float blink_freq = 16000; // Reduce SM clock to keep flash visible... float blink_div = (float)clock_get_hz(clk_sys) / blink_freq; // ... calculate the required blink SM clock divider static const float rotary_freq = 16000; // Clock speed reduced to eliminate rotary encoder jitter... float rotary_div = (float)clock_get_hz(clk_sys) / rotary_freq; //... then calculate the required rotary encoder SM clock divider float DAC_freq, DAC_div; set_sys_clock_khz(280000, true); // Overclocking the core by a factor of 2 allows 1MHz from DAC stdio_init_all(); // needed for printf // Set up the GPIO pins... const uint Onboard_LED = PICO_DEFAULT_LED_PIN; // Debug use - intialise the Onboard LED... gpio_init(Onboard_LED); gpio_set_dir(Onboard_LED, GPIO_OUT); // Initialise the Nixie cathodes... for ( uint i = 0; i < sizeof(NixieCathodes) / sizeof( NixieCathodes[0]); i++ ) { gpio_init(NixieCathodes[i]); gpio_set_dir(NixieCathodes[i], GPIO_OUT); // Set as output } // Initialise the Nixe anodes... for ( uint i = 0; i < sizeof(NixieAnodes) / sizeof( NixieAnodes[0]); i++ ) { gpio_init(NixieAnodes[i]); gpio_set_dir(NixieAnodes[i], GPIO_OUT); // Set as output } // Initialise the rotary encoder... for ( uint i = 0; i < sizeof(RotaryEncoder) / sizeof( EncoderPorts[0]); i++ ) { gpio_init(EncoderPorts[i]); gpio_set_dir(EncoderPorts[i], GPIO_IN); // Set as input gpio_pull_up(EncoderPorts[i]); // Enable pull up } // Initialise the 3-way switch inputs... gpio_init(SW_3way_1); gpio_set_dir(SW_3way_1, GPIO_IN); gpio_pull_up(SW_3way_1); gpio_init(SW_3way_2); gpio_set_dir(SW_3way_2, GPIO_IN); gpio_pull_up(SW_3way_2); unsigned short DAC_data[sine_table_size] __attribute__ ((aligned(2048))) ; int i ; // Sine wave table... for (i=0; i<(sine_table_size); i++) { // raw_sin[i] = (int)(2047 * sin((float)i*6.283/(float)sine_table_size) + 2047); // 12 bit raw_sin[i] = (int)(16 * sin((float)i*6.283/(float)sine_table_size) + 16); // 5 bit DAC_data[i] = raw_sin[i] ; // memory alligned data } /* // SawTooth wave table... for (i=0; i<(sine_table_size); i++) { DAC_data[i] = i%32; // 5 bit } */ /* // Reverse SawTooth wave table... for (i=0; i<(sine_table_size); i++) { DAC_data[i] = 32-i%32; // 5 bit } */ /* // Triangular wave table... for (i=0; i<(sine_table_size); i++) { DAC_data[i] = abs((i % 64)-31); // 5 bit. triangular wave of period 64, oscillating between 0 and 31 } */ // Confirm memory alignment printf("\nConfirm memory alignment...\nBeginning: %x", &DAC_data[0]); printf("\nFirst: %x", &DAC_data[1]); printf("\nSecond: %x\n\n", &DAC_data[2]); // Set up the State machines... PIO pio = pio0; uint offset = pio_add_program(pio, &pio_blink_program); blink_forever my_blinker(pio, 0, offset, 25, blink_freq, blink_div); // SM0=>onboard LED RotaryEncoder my_encoder(16, rotary_freq); // the A of the rotary encoder is connected to GPIO 16, B to GPIO 17 my_encoder.set_Frequency(17); // Lowest frequency that will work with FastDAC.pio my_encoder.set_WaveForm(0); // Default: Sine wave my_encoder.set_Level(50); // Default: 50% // Select a PIO and find a free state machine on it (erroring if there are none). // Configure the state machine to run our program, and start it, using the helper function we included in our .pio file. pio = pio1; offset = pio_add_program(pio, &pio_FastDAC_program); uint sm_FastDAC = pio_claim_unused_sm(pio, true); pio_FastDAC_program_init(pio, sm_FastDAC, offset, 2); offset = pio_add_program(pio, &pio_SlowDAC_program); uint sm_SlowDAC = pio_claim_unused_sm(pio, true); pio_SlowDAC_program_init(pio, sm_SlowDAC, offset, 2); // Get 2 x free DMA channels for the Fast DAC - panic() if there are none int fast_ctrl_chan = dma_claim_unused_channel(true); int fast_data_chan = dma_claim_unused_channel(true); printf("FastDAC:\n"); printf("PIO:%d SM:%d\n", 1, sm_FastDAC); printf("DMA:%d ctrl channel\n", fast_ctrl_chan); printf("DMA:%d data channel\n\n", fast_data_chan); // Setup the Fast 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(fast_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( fast_ctrl_chan, &fc, &dma_hw->ch[fast_data_chan].al1_transfer_count_trig, // txfer to transfer count trigger &transfer_count, 1, false ); // Setup the Fast DAC data channel... // 32 bit transfers. Read address increments after each transfer. fc = dma_channel_get_default_config(fast_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, don't increment write address channel_config_set_write_increment(&fc, false); channel_config_set_dreq(&fc, pio_get_dreq(pio, sm_FastDAC, true)); // Transfer when PIO SM TX FIFO has space channel_config_set_chain_to(&fc, fast_ctrl_chan); // chain to the controller DMA channel channel_config_set_ring(&fc, false, 9); // 1 << 9 byte boundary on read ptr // set wrap boundary. This is why we needed alignment! dma_channel_configure( fast_data_chan, // Channel to be configured &fc, // The configuration we just created &pio->txf[sm_FastDAC], // Write to FIFO DAC_data, // The initial read address (AT NATURAL ALIGNMENT POINT) sine_table_size, // Number of transfers; in this case each is 2 byte. false // Don't start immediately. ); // Get 2 x free DMA channels for the Slow DAC - panic() if there are none int slow_ctrl_chan = dma_claim_unused_channel(true); int slow_data_chan = dma_claim_unused_channel(true); printf("SlowDAC:\n"); printf("PIO:%d SM:%d\n", 1, sm_SlowDAC); printf("DMA:%d ctrl channel\n", slow_ctrl_chan); printf("DMA:%d data channel\n\n", slow_data_chan); // Setup the Slow 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 sc = dma_channel_get_default_config(slow_ctrl_chan); // default configs channel_config_set_transfer_data_size(&sc, DMA_SIZE_32); // 32-bit txfers channel_config_set_read_increment(&sc, false); // no read incrementing channel_config_set_write_increment(&sc, false); // no write incrementing dma_channel_configure( slow_ctrl_chan, &sc, &dma_hw->ch[slow_data_chan].al1_transfer_count_trig, // txfer to transfer count trigger &transfer_count, 1, false ); // Setup the slow DAC data channel... // 32 bit transfers. Read address increments after each transfer. sc = dma_channel_get_default_config(slow_data_chan); channel_config_set_transfer_data_size(&sc, DMA_SIZE_32); // 32-bit txfers channel_config_set_read_increment(&sc, true); // increment the read adddress, don't increment write address channel_config_set_write_increment(&sc, false); channel_config_set_dreq(&sc, pio_get_dreq(pio, sm_SlowDAC, true)); // Transfer when PIO SM TX FIFO has space channel_config_set_chain_to(&sc, slow_ctrl_chan); // chain to the controller DMA channel channel_config_set_ring(&sc, false, 9); // 1 << 9 byte boundary on read ptr // set wrap boundary. This is why we needed alignment! dma_channel_configure( slow_data_chan, // Channel to be configured &sc, // The configuration we just created &pio->txf[sm_SlowDAC], // Write to FIFO DAC_data, // The initial read address (AT NATURAL ALIGNMENT POINT) sine_table_size, // Number of transfers; in this case each is 2 byte. false // Don't start immediately. ); // Create a repeating timer that calls Repeating_Timer_Callback. // If the delay is > 0 then this is the delay between the previous callback ending and the next starting. If the delay is negative // then the next call to the callback will be exactly 7ms after the start of the call to the last callback. struct repeating_timer timer; add_repeating_timer_ms(-7, Repeating_Timer_Callback, NULL, &timer); // 7ms - Short enough to avoid Nixie tube flicker // Long enough to avoid Nixie tube bluring while (true) { // Infinite loop to print the current rotation if ((my_encoder.get_Frequency() != LastFrequency) || (my_encoder.get_WaveForm() != LastWaveForm) || (my_encoder.get_Level() != LastLevel)) { // Falls through here when the rotary encoder value changes... switch (SW_3way) { case 0b010: // Frequency temp = my_encoder.get_Frequency(); if (temp >= 17) { // If DAC_div exceeds 2^16 (65,536), the registers wrap around, and the State Machine clock will be incorrect. // A slower version of the DAC State Machine is used for frequencies below 17Hz, allowing the DAC_div to be kept // within range. // FastDAC ( 17Hz=>1Mhz ) DAC_freq = temp*256000; // Target frequency... DAC_div = (float)clock_get_hz(clk_sys) / DAC_freq; // ...calculate the required rotary encoder SM clock divider pio_sm_set_clkdiv(pio1, sm_FastDAC, DAC_div ); pio_sm_set_enabled(pio, sm_SlowDAC, false); // Stop the SlowDAC State MAchine pio_sm_set_enabled(pio, sm_FastDAC, true); // Start the FastDAC State Machine dma_start_channel_mask(1u << fast_ctrl_chan); // Start the FastDAC DMA channel } else { // SlowDAC ( 1Hz=>16Hz ) DAC_freq = temp*256; // Target frequency... DAC_div = (float)clock_get_hz(clk_sys) / DAC_freq; // ...calculate the required rotary encoder SM clock divider DAC_div = DAC_div / 32; // Adjust to keep DAC_div within useable range pio_sm_set_clkdiv(pio1, sm_SlowDAC, DAC_div ); pio_sm_set_enabled(pio, sm_FastDAC, false); // Stop the FastDAC State Machine pio_sm_set_enabled(pio, sm_SlowDAC, true); // Start the SlowDAC State MAchine dma_start_channel_mask(1u << slow_ctrl_chan); // Start the SlowDAC DMA channel } printf("Rotation: %03d - SM Div: %8.4f - SM Clk: %06.0gHz - Fout: %3.0fHz\n",temp, DAC_div, DAC_freq, DAC_freq/256); LastFrequency = temp; NixieBuffer[0] = temp % 10 ; // First Nixie ( 1's ) temp /= 10 ; // finished with temp, so ok to trash it. temp=>10's NixieBuffer[1] = temp % 10 ; // Second Nixie ( 10's ) temp /= 10 ; // temp=>100's NixieBuffer[2] = temp % 10 ; // Third Nixie ( 100's ) break; case 0b011: // Waveform temp = my_encoder.get_WaveForm(); switch (temp) { case 0: printf("Rotation: %03d - Sine\n",temp); break; case 1: printf("Rotation: %03d - Sawtooth (rising)\n",temp); break; case 2: printf("Rotation: %03d - Sawtooth (falling)\n",temp); break; case 3: printf("Rotation: %03d - Triangle\n",temp); break; case 4: printf("Rotation: %03d - Square\n",temp); break; } LastWaveForm = temp; NixieBuffer[0] = temp % 10 ; // First Nixie ( 1's ) temp /= 10 ; // finished with temp, so ok to trash it. temp=>10's NixieBuffer[1] = temp % 10 ; // Second Nixie ( 10's ) temp /= 10 ; // temp=>100's NixieBuffer[2] = 10 ; // Blank Third Nixie ( 100's ) break; case 0b001: // Level temp = my_encoder.get_Level(); printf("Rotation: %03d\n",temp); LastLevel = temp; NixieBuffer[0] = temp % 10 ; // First Nixie ( 1's ) temp /= 10 ; // finished with temp, so ok to trash it. temp=>10's NixieBuffer[1] = temp % 10 ; // Second Nixie ( 10's ) temp /= 10 ; // temp=>100's NixieBuffer[2] = 10 ; // Blank Third Nixie ( 100's ) } } // Get 3 way toggle switch status... SW_3way = (gpio_get(SW_3way_1)<<1) + (gpio_get(SW_3way_2)); // 0b010 - Top position // 0b001 - Bottom position // 0b011 - Middle position if ( SW_3way != Last_SW_3way) { switch (SW_3way) { // DEBUG - Print 3 way switch status case 0b010: printf("Frequency:\n"); break; // Top case 0b011: printf("Waveform:\n"); break; // Middle case 0b001: printf("Level:\n"); break; // Bottom // case 0b000: printf("Undefined:\n"); // Impossible combination } Last_SW_3way = SW_3way; } } }