# HG changeset patch
# User Jan Mulder <jlmulder@xs4all.nl>
# Date 1554209595 -7200
# Node ID f9ba924d188ef93b7df8916313f07682fd126401
# Parent  d5891007fc4ca5fc0c27d8c9d420a887cf089b51
Bugfix: set battery percentage correctly after RTE update

When the RTE is rebooted, the battery percentage on the display is zeroed.
However, when selecting SYS2-reboot-maintenance, the previously known
battery percentage can be manually restored. Interestingly, when
the restore reported a percentage A, choosing that resulted in a
percentage B to be displayed again. With B much smaller than A.
So, rebooting the RTE multiple times resulted in an seemingly
empty battery, while it definitely is not.

The reason for this is a relatively simple bug in the RTE code. This
commit fixes the conversion between the internal LTC2941 registers
and the percentage value to be displayed. Obviously, from and to
the internal registers need to be symmetrical.

Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>

diff -r d5891007fc4c -r f9ba924d188e Small_CPU/Src/batteryGasGauge.c
--- a/Small_CPU/Src/batteryGasGauge.c	Tue Apr 02 18:18:22 2019 +0200
+++ b/Small_CPU/Src/batteryGasGauge.c	Tue Apr 02 14:53:15 2019 +0200
@@ -27,11 +27,11 @@
 #include "stm32f4xx_hal.h"
 #include "i2c.h"
 
-float battery_f_voltage = 0;
-float battery_f_charge_percent = 0;
+static float battery_f_voltage = 0;
+static float battery_f_charge_percent = 0;
 
 #define BGG_BATTERY_OFFSET          (26123)  //; 65536-(3,35Ah/0,085mAh)
-#define BGG_BATTERY_DEVIDER         (394)    //; 3,35Ah/0,085mAh/100 [%]
+#define BGG_BATTERY_DIVIDER         (394)    //; 3,35Ah/0,085mAh/100 [%]
 
 float get_voltage(void)
 {
@@ -61,8 +61,14 @@
 	
 	uint8_t buffer[2];
 	buffer[0] = 0x01;
-	buffer[1] = 0xF8;// true: F8 = 11111000, wrong/old comment: 11101000
-	I2C_Master_Transmit(  DEVICE_BATTERYGAUGE, buffer, 2);
+
+	// F8 = 11111000:
+	// Vbat 3.0V (11)
+	// Prescale M = 128 (111)
+	// AL/CC pin disable (0)
+	// Shutdown (0)
+	buffer[1] = 0xF8;
+	I2C_Master_Transmit(DEVICE_BATTERYGAUGE, buffer, 2);
 }
 
 
@@ -86,7 +92,7 @@
 	battery_f_charge_percent_local =  (float)(bufferReceive[2] * 256);
 	battery_f_charge_percent_local += (float)(bufferReceive[3]);
 	battery_f_charge_percent_local -= BGG_BATTERY_OFFSET;
-	battery_f_charge_percent_local /= BGG_BATTERY_DEVIDER;
+	battery_f_charge_percent_local /= BGG_BATTERY_DIVIDER;
 	
 	if(battery_f_charge_percent_local < 0)
 		battery_f_charge_percent_local = 0;
@@ -120,8 +126,9 @@
 	
 	if(percentage >= 100)
 		mAhSend = 0xFFFF;
-	else	
-		mAhSend = (uint16_t)(percentage * 655.35f);
+	else {
+		mAhSend = (percentage * BGG_BATTERY_DIVIDER) + BGG_BATTERY_OFFSET;
+	}
 	
 	uint8_t bufferSend[3];
 	bufferSend[0] = 0x02;