init can bus

CmakeLists.txt

@@ -18,6 +18,8 @@ project(test C CXX ASM)
 pico_sdk_init()
 
 
+# == NODE 1 ==
+
 # the executable
 add_executable( node1 node1.c bme280.c pms5003.c )
 pico_set_program_version(node1 "0.1")
@@ -29,6 +31,8 @@ target_link_libraries( node1 pico_stdlib hardware_i2c)
 # create map/bin/hex file etc.
 pico_add_extra_outputs( node1 )
 
+# == WIFI SCAN ==
+
 add_executable(wifi_scan wifi_scan.c)
 target_include_directories(wifi_scan PRIVATE
     ${CMAKE_CURRENT_LIST_DIR}
@@ -42,6 +46,7 @@ target_link_libraries(wifi_scan
 
 pico_add_extra_outputs(wifi_scan)
 
+# == MQTT TEST ==
 
 # Define the host name of the MQTT server in an environment variable or pass it to cmake,
 # e.g. cmake -DMQTT_SERVER=myserver ..
@@ -94,3 +99,11 @@ target_compile_definitions(${TARGET_NAME} PRIVATE
     )
 
 pico_add_extra_outputs(${TARGET_NAME})
+
+# == CAN BUS SENDER TEST ==
+
+add_executable( can_bus_sender_test can_bus_sender_test.c can_bus.c )
+pico_set_program_version(can_bus_sender_test "0.1")
+pico_set_program_name(can_bus_sender_test "Can Bus Sender Test")
+target_link_libraries(can_bus_sender_test pico_stdlib hardware_spi)
+pico_add_extra_outputs(can_bus_sender_test)

can_bus.c

@@ -0,0 +1,109 @@
+#include "can_bus.h"
+
+// https://docs.cirkitdesigner.com/component/a4fea22c-a62d-453b-8645-1c8efe324cbc/mcp2515
+// https://learn.adafruit.com/adafruit-picowbell-can-bus-for-pico/overview
+// Pico Lib: https://github.com/adamczykpiotr/pico-mcp2515
+// Arduino Lib: https://github.com/autowp/arduino-mcp2515
+// MCP2515 is the cheap aliexpress boards I have
+
+// spi_inst_t* CHANNEL = spi0;
+// uint32_t SPI_CLOCK = DEFAULT_SPI_CLOCK
+//
+//
+
+// 10000000 //10Mhz
+#define MCP_SPI_CLOCK 5000000 // 5Mhz
+#define MCP_INSTRUCTION_RESET 0xC0
+#define MCP_INSTRUCTION_WRITE 0x02
+
+void mcp2515_init(mcp2515_config *config, uint8_t cs_pin, uint8_t tx_pin,
+                  uint8_t rx_pin, uint8_t sck_pin, spi_inst_t *spi_inst) {
+  config->CHANNEL = spi_inst;
+  config->CS_PIN = cs_pin;
+
+  spi_init(config->CHANNEL, MCP_SPI_CLOCK);
+  gpio_set_function(rx_pin, GPIO_FUNC_SPI);
+  gpio_set_function(sck_pin, GPIO_FUNC_SPI);
+  gpio_set_function(tx_pin, GPIO_FUNC_SPI);
+  spi_set_format(config->CHANNEL, 8, SPI_CPOL_0, SPI_CPHA_0, SPI_MSB_FIRST);
+
+  // Chip select is active-low, so we'll initialise it to a driven-high state
+  gpio_init(config->CS_PIN);
+  gpio_set_dir(config->CS_PIN, GPIO_OUT);
+  // gpio_put(cs_pin, 0);
+}
+
+static void mcp2515_start_spi(mcp2515_config *config) {
+  asm volatile("nop \n nop \n nop");
+  gpio_put(config->CS_PIN, 0);
+  asm volatile("nop \n nop \n nop");
+}
+
+static void mcp2515_end_spi(mcp2515_config *config) {
+  asm volatile("nop \n nop \n nop");
+  gpio_put(config->CS_PIN, 1);
+  asm volatile("nop \n nop \n nop");
+}
+
+static void mcp2515_set_registers(mcp2515_config *config, const uint8_t reg,
+                                  const uint8_t values[], const uint8_t n) {
+  mcp2515_start_spi(config);
+  uint8_t data[2] = {MCP_INSTRUCTION_WRITE, reg};
+  spi_write_blocking(config->CHANNEL, data, 2);
+  spi_write_blocking(config->CHANNEL, values, n);
+  mcp2515_end_spi(config);
+}
+
+enum MCP_ERROR mcp2515_reset(mcp2515_config *config) {
+  mcp2515_start_spi(config);
+  uint8_t instruction = MCP_INSTRUCTION_RESET;
+  spi_write_blocking(config->CHANNEL, &instruction, 1);
+  mcp2515_end_spi(config);
+  sleep_ms(10);
+
+  uint8_t zeros[14];
+  memset(zeros, 0, sizeof(zeros));
+  // setRegisters(MCP_TXB0CTRL, zeros, 14);
+  // setRegisters(MCP_TXB1CTRL, zeros, 14);
+  // setRegisters(MCP_TXB2CTRL, zeros, 14);
+
+  // setRegister(MCP_RXB0CTRL, 0);
+  // setRegister(MCP_RXB1CTRL, 0);
+
+  // setRegister(MCP_CANINTE,
+  //             CANINTF_RX0IF | CANINTF_RX1IF | CANINTF_ERRIF | CANINTF_MERRF);
+
+  // receives all valid messages using either Standard or Extended Identifiers
+  // that meet filter criteria. RXF0 is applied for RXB0, RXF1 is applied for
+  // RXB1
+  // modifyRegister(MCP_RXB0CTRL,
+  //                RXBnCTRL_RXM_MASK | RXB0CTRL_BUKT | RXB0CTRL_FILHIT_MASK,
+  //                RXBnCTRL_RXM_STDEXT | RXB0CTRL_BUKT | RXB0CTRL_FILHIT);
+  // modifyRegister(MCP_RXB1CTRL, RXBnCTRL_RXM_MASK | RXB1CTRL_FILHIT_MASK,
+  //                RXBnCTRL_RXM_STDEXT | RXB1CTRL_FILHIT);
+
+  // clear filters and masks
+  // do not filter any standard frames for RXF0 used by RXB0
+  // do not filter any extended frames for RXF1 used by RXB1
+  // RXF filters[] = {RXF0, RXF1, RXF2, RXF3, RXF4, RXF5};
+  // for (int i = 0; i < 6; i++) {
+  //   bool ext = (i == 1);
+  //   ERROR result = setFilter(filters[i], ext, 0);
+  //   if (result != ERROR_OK) {
+  //     return result;
+  //   }
+  // }
+
+  // MASK masks[] = {MASK0, MASK1};
+  // for (int i = 0; i < 2; i++) {
+  //   ERROR result = setFilterMask(masks[i], true, 0);
+  //   if (result != ERROR_OK) {
+  //     return result;
+  //   }
+  // }
+
+  return ERROR_OK;
+}
+
+// mcp2515.setBitrate(CAN_125KBPS);
+// mcp2515.setLoopbackMode();

can_bus.h

@@ -0,0 +1,38 @@
+#include "boards/pico.h"
+#include "hardware/spi.h"
+#include "pico/stdlib.h"
+#include "pico/time.h"
+
+// 16MHz 125Kbps
+#define MCP_CFG1 (0x03)
+#define MCP_CFG2 (0xF0)
+#define MCP_CFG3 (0x86)
+
+typedef struct {
+  spi_inst_t *CHANNEL;
+  uint8_t CS_PIN;
+  // uint8_t TX_PIN;
+  // uint8_t RX_PIN;
+  // uint8_t SCK_PIN;
+  // uint32_t SPI_CLOCK;
+} mcp2515_config;
+
+struct can_frame {
+  uint32_t can_id; // 32 bit CAN_ID + EFF/RTR/ERR flags
+  char can_dlc;    //  frame payload length in byte (0 .. CAN_MAX_DLEN) */
+  char data[8];    // msg
+};
+
+enum MCP_ERROR {
+  ERROR_OK = 0,
+  ERROR_FAIL = 1,
+  ERROR_ALLTXBUSY = 2,
+  ERROR_FAILINIT = 3,
+  ERROR_FAILTX = 4,
+  ERROR_NOMSG = 5
+};
+
+void mcp2515_init(mcp2515_config *config, uint8_t cs_pin, uint8_t tx_pin,
+                  uint8_t rx_pin, uint8_t sck_pin, spi_inst_t *spi_inst);
+enum MCP_ERROR sendMessage(const struct can_frame *frame);
+enum MPC_ERROR readMessage(struct can_frame *frame);

can_bus_sender_test.c

@@ -0,0 +1,20 @@
+#include "pico/stdlib.h"
+#include <hardware/gpio.h>
+#include <hardware/spi.h>
+#include "can_bus.h"
+
+static mcp2515_config can_bus_config;
+
+int main() {
+  stdio_init_all();
+
+  // Setup BME280
+  mcp2515_init(&can_bus_config, 13, 11, 12, 10, spi1);
+
+  while (true) {
+    // TODO: send message
+    // mcp2515.reset();
+    sleep_ms(1000);
+    // tight_loop_contents();
+  }
+}