Ch32x03x i2c sensor example

ch32fun/ch32fun.h

@@ -875,6 +875,9 @@ extern "C" {
 #define DELAY_MS_TIME ((FUNCONF_SYSTEM_CORE_CLOCK)/8000)
 #endif
 
+#define DELAY_MSEC_COUNT(n) (DELAY_MS_TIME * n)
+#define DELAY_SEC_COUNT(n) (DELAY_MS_TIME * 1000 * n)
+
 #define Delay_Us(n) DelaySysTick( (n) * DELAY_US_TIME )
 #define Delay_Ms(n) DelaySysTick( (n) * DELAY_MS_TIME )
 

examples_x035/i2c_sensor_test/Makefile

@@ -0,0 +1,11 @@
+all : flash
+
+TARGET:=i2c_sensor_test
+TARGET_MCU:=CH32X033
+
+include ../../ch32fun/ch32fun.mk
+
+flash : cv_flash
+clean : cv_clean
+
+

examples_x035/i2c_sensor_test/README.md

@@ -0,0 +1,50 @@
+# I2C Master Communication Example
+
+This example demonstrates I2C communication with an I2C slave device.
+You can use this with (one or the other):
+- BH1750 light sensor (actual hardware)
+- Another CH32X035 running i2c_slave_test firmware
+
+if you are connecting a CH32X03X to a BH1750, the default slave address for the sensor is 0x23
+if you are connecting to another CH32X03X, the default slave address for the slave CH32X03X is 0x66
+For the CH32X03X slave, it needs to run the `i2c_slave_test` example
+
+Setup for BH1750 sensor:
+- Connect SCL to PA10 (I2C1 SCL)
+- Connect SDA to PA11 (I2C1 SDA)
+
+Setup for CH32X03X slave:
+- Connect both boards to the same I2C bus
+- Connect SCL (PA10) of both boards together
+- Connect SDA (PA11) of both boards together
+
+Expected output readings from CH32X03X slave:
+Read 1 byte (cmd 0x01): 0x11
+Read 2 bytes (cmd 0x13): 0x5D 0x66 
+Read 4 bytes (cmd 0x14): 0x77 0x88 0x99 0xAA 
+write buffer (cmd 0x31): successful
+Read buffer (cmd 0x30): 0xAA 0xBB 0xCC 0xFF 0xFF 
+
+0x3x Slave Command Set:
+0x01 - Minick BH1750 Power on command (returns 1 byte)
+0x23 - Minmick BH1750 Resolution command (returns 1 byte) 
+0x13 - Read 2 bytes from slave
+0x14 - Read 4 bytes from slave
+0x30 - Read from slave's writable buffer (32 bytes)
+0x31 - Write to slave's writable buffer (32 bytes)
+
+Command 0x30: Read from writable buffer
+Format: { 0x30, start_index }
+- start_index: Position to start reading from (0-31)
+Since buffer size is 32 bytes (0-31), reading from index 29:
+- Returns bytes 29, 30, 31 (3 valid bytes)
+- Remaining requested bytes return 0xFF (buffer boundary exceeded)
+
+Command 0x31: Write to writable buffer  
+Format: { 0x31, start_index, data0, data1, ... }
+- start_index: Position to start writing to (0-31)
+- dataX: Bytes to write (up to buffer boundary)
+Since buffer ends at index 31:
+- Writes 0xAA to index 29, 0xBB to index 30, 0xCC to index 31
+- 0xDD is not written (buffer full)
+- Returns success for written bytes only

examples_x035/i2c_sensor_test/funconfig.h

@@ -0,0 +1,7 @@
+#ifndef _FUNCONFIG_H
+#define _FUNCONFIG_H
+
+#define FUNCONF_USE_DEBUGPRINTF 1
+
+#endif
+

examples_x035/i2c_sensor_test/i2c_sensor_test.c

@@ -0,0 +1,143 @@
+#define FUNCONF_SYSTICK_USE_HCLK 1
+
+#include "ch32fun.h"
+#include <stdio.h>
+#include "lib_i2c.h"
+
+#define I2C_TARGET I2C1
+#define SYSTEM_CLOCK_HZ 48000000
+
+// #define I2C_ADDRESS 0x23		// use this for BH1750
+#define I2C_ADDRESS 0x66		// use this for i2c_slave_test
+
+u8 read_state = 0;
+
+void print_ch32_readings(I2C_TypeDef* I2Cx, u8 i2_addr) {
+	u8 rx_buf[8];
+	u8 read, err;
+
+	switch (read_state) {
+		case 0:
+			// read command 0x01: return 1 byte
+			err = i2c_readReg_buffer(I2Cx, i2_addr, 0x01, rx_buf, 1);
+			if (!err) {
+				printf("\nRead 1 byte (cmd 0x01): 0x%02X", rx_buf[0]);
+			} else {
+				printf("\nError 0x%02X", err);
+			}
+			break;
+
+		case 1:
+			// read command 0x10: return 2 bytes
+			err = i2c_readReg_buffer(I2Cx, i2_addr, 0x13, rx_buf, 2);
+			if (!err) {
+				printf("\nRead 2 bytes (cmd 0x13): ");
+				for (int i = 0; i < 2; i++) {
+					printf("0x%02X ", rx_buf[i]);
+				}
+			} else {
+				printf("\nError 0x%02X", err);
+			}
+
+			break;
+
+		case 2:
+			// read command 0x11: return 4 bytes
+			err = i2c_readReg_buffer(I2Cx, i2_addr, 0x14, rx_buf, 4);
+
+			if (!err) {
+				printf("\nRead 4 bytes (cmd 0x14): ");
+				for (int i = 0; i < 4; i++) {
+					printf("0x%02X ", rx_buf[i]);
+				}
+			} else {
+				printf("\nError 0x%02X", err);
+			}
+			break;
+
+		case 3:
+			{
+				// write command 0x31. write buffer
+				u8 write_request[] = { 0x31, 29, 0xAA, 0xBB, 0xCC, 0xDD };
+				err = i2c_sendBytes(I2Cx, i2_addr, &write_request, sizeof(write_request));
+
+				if (!err) {
+					printf("\nwrite buffer (cmd 0x%02X): successful", 0x31);
+				}
+				if (err) {
+					printf("\nError 0x%02X", err);
+				}
+				break;
+			}
+
+		case 4:
+			{
+				// read command 0x30: read buffer
+				u8 read_request[] = { 0x30, 29 };
+				err = i2c_readRegTx_buffer(I2Cx, i2_addr, &read_request, sizeof(read_request), &rx_buf, 5);
+
+				if (!err) {
+					printf("\nRead buffer (cmd 0x30): ");
+					for (int i = 0; i < 5; i++) {
+						printf("0x%02X ", rx_buf[i]);
+					}
+				} else {
+					printf("\nError 0x%02X", err);
+				}
+				printf("\n");
+				break;
+			}
+
+		default:
+			break;
+	}
+
+	read_state++;
+	if (read_state > 4) read_state = 0;
+}
+
+u16 get_bh1750_readings(I2C_TypeDef* I2Cx, u8 i2cAddress) {
+	u8 data[2];
+	i2c_readReg_buffer(I2Cx, i2cAddress, 0x13, data, 2);	// get Reading
+	u16 raw = (data[0] << 8) | data[1];
+	return raw * 12 / 10;  // Convert to lux
+}
+
+void onHandle_ping(u8 i2cAddress) {
+	printf("Found device: 0x%02X\n", i2cAddress);
+}
+
+int main() {
+	SystemInit();
+	funGpioInitAll(); // Enable GPIOs
+
+	printf("\n~ I2C sensors Example ~\n");
+	printf("Chip ID: %08lX\n", ESIG->UID0);
+	printf("Chip Capacity: %d KB\n", ESIG->CAP);
+
+	funPinMode(PA10, GPIO_CFGLR_OUT_50Mhz_AF_PP);	// I2C1 SCL
+	funPinMode(PA11, GPIO_CFGLR_OUT_50Mhz_AF_PP);  // I2C1 SDA
+
+	i2c_init(I2C_TARGET, FUNCONF_SYSTEM_CORE_CLOCK, 100000);
+	printf("Scanning I2C Bus...\n");
+	i2c_scan(I2C_TARGET, onHandle_ping);
+	printf("\nDone.\n");
+
+	i2c_sendByte(I2C_TARGET, I2C_ADDRESS, 0x01); // Power on
+	i2c_sendByte(I2C_TARGET, I2C_ADDRESS, 0x23); // resolution
+
+	u32 time_ref = 0;
+
+	while(1) {
+		if (TimeElapsed32(SysTick->CNT, time_ref) > DELAY_MSEC_COUNT(200)) {
+			time_ref = SysTick->CNT;
+
+			#if I2C_ADDRESS == 0x23
+				u16 lux = get_bh1750_readings(I2C_TARGET, I2C_ADDRESS);
+				printf("BH1750 Reading: %d lx\n", lux);
+			#else
+				print_ch32_readings(I2C_TARGET, I2C_ADDRESS);
+			#endif
+		}
+	}
+}

examples_x035/i2c_slave_test/Makefile

@@ -0,0 +1,11 @@
+all : flash
+
+TARGET:=i2c_slave_test
+TARGET_MCU:=CH32X033
+
+include ../../ch32fun/ch32fun.mk
+
+flash : cv_flash
+clean : cv_clean
+
+

examples_x035/i2c_slave_test/funconfig.h

@@ -0,0 +1,7 @@
+#ifndef _FUNCONFIG_H
+#define _FUNCONFIG_H
+
+#define FUNCONF_USE_DEBUGPRINTF 1
+
+#endif
+