From 917886820dad7caeb9541d4e0b645700229b422c Mon Sep 17 00:00:00 2001
From: dooku <mj370@protonmail.com>
Date: Wed, 6 Oct 2021 20:20:51 +0200
Subject: [PATCH] WIP holding register write

---
 fw/Core/Src/config.c           |  2 +-
 fw/Core/Src/modbus.c           | 20 +++++++++-----
 tests/holding_register_test.py | 49 ++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 7 deletions(-)
 create mode 100755 tests/holding_register_test.py

diff --git a/fw/Core/Src/config.c b/fw/Core/Src/config.c
index 676afb2..328e711 100644
--- a/fw/Core/Src/config.c
+++ b/fw/Core/Src/config.c
@@ -97,7 +97,7 @@ int8_t config_write(config_t *config)
 	}
 
 	/* Write LED BRIGHTNESS */
-	if (eeprom_program_word(CONFIG_EEPROM_ADDR_LED_BRIGHTNESS, config->led_brightness)  != EEPROM_OK)
+	if (eeprom_program_halfword(CONFIG_EEPROM_ADDR_LED_BRIGHTNESS, config->led_brightness)  != EEPROM_OK)
 	{
 		return EEPROM_WRITE_ERROR;
 	}
diff --git a/fw/Core/Src/modbus.c b/fw/Core/Src/modbus.c
index 854c7e8..9c06664 100644
--- a/fw/Core/Src/modbus.c
+++ b/fw/Core/Src/modbus.c
@@ -180,12 +180,20 @@ int8_t modbus_slave_process_msg(const uint8_t *buffer, int len)
 			return MODBUS_ERROR;
 		}
 		transaction.register_address = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
-		transaction.register_count = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
-		if (
-				transaction.register_count < 1 ||
-				transaction.register_count > MODBUS_MAX_REGISTERS
-		   ) {
-			transaction.exception.exception_code = MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE;
+		if (flags & MODBUS_FLAG_WRITE) {
+			if (flags & MODBUS_FLAG_SINGLE) {
+				transaction.holding_registers[0] = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
+			} else {
+				// write multiple register - TODO
+			}
+		} else {
+			transaction.register_count = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
+			if (
+					transaction.register_count < 1 ||
+					transaction.register_count > MODBUS_MAX_REGISTERS
+			   ) {
+				transaction.exception.exception_code = MODBUS_EXCEPTION_ILLEGAL_DATA_VALUE;
+			}
 		}
 		// add offset to register number
 		transaction.register_number += transaction.register_address;
diff --git a/tests/holding_register_test.py b/tests/holding_register_test.py
new file mode 100755
index 0000000..007fd7e
--- /dev/null
+++ b/tests/holding_register_test.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+from time import sleep
+import minimalmodbus
+import serial
+
+slave_address = 254
+instrument = minimalmodbus.Instrument('/dev/ttyUSB0', slave_address, close_port_after_each_call=True)  # port name, slave address (in decimal)
+
+instrument.serial.baudrate = 19200
+instrument.serial.bytesize = 8
+instrument.serial.parity   = serial.PARITY_EVEN
+instrument.serial.stopbits = 1
+instrument.serial.timeout  = 0.05          # seconds
+instrument.mode = minimalmodbus.MODE_RTU   # rtu or ascii mode
+instrument.clear_buffers_before_each_transaction = True
+
+# holding register numbers
+LED_on_register = 0
+LED_brightness_register = 1
+LED_smooth_register = 2
+CO2_alert_limit_1_register = 3
+CO2_alert_limit_2_register = 4
+SCD4x_temperature_offset_register = 5
+MODBUS_address_register = 6
+baudrate_register = 7
+# holding register readout
+print('---- Reading from holding registers ----')
+#LED_on = int(instrument.read_register(LED_on_register, 1, functioncode=3) * 10)
+#LED_brightness = int(instrument.read_register(LED_brightness_register, 1, functioncode=3) * 10)
+#LED_smooth = int(instrument.read_register(LED_smooth_register, 1, functioncode=3) * 10)
+#CO2_alert_limit_1 = int(instrument.read_register(CO2_alert_limit_1_register, 1, functioncode=3) * 10)
+#CO2_alert_limit_2 = int(instrument.read_register(CO2_alert_limit_2_register, 1, functioncode=3) * 10)
+#SCD4x_temperature_offset = int(instrument.read_register(SCD4x_temperature_offset_register, 1, functioncode=3) * 10)
+#MODBUS_address = int(instrument.read_register(MODBUS_address_register, 1, functioncode=3) * 10)
+#baudrate = int(instrument.read_register(baudrate_register, 1, functioncode=3) * 10)
+# print
+#print(
+#f'''LED_on = {LED_on}
+#LED_brightness = {LED_brightness}
+#LED_smooth = {LED_smooth}
+#CO2_alert_limit_1 = {CO2_alert_limit_1}
+#CO2_alert_limit_2 = {CO2_alert_limit_2}
+#SCD4x_temperature_offset = {SCD4x_temperature_offset}
+#MODBUS_address = {MODBUS_address}
+#baudrate = {baudrate}
+#''')
+# write to holding register
+print('---- Writing to holding registers ----)')
+instrument.write_register(LED_on_register, 0, functioncode=6)