bug fix for REG_ID_BAT

The correct power-on sequence for obtaining the battery percentage is to first power on the PicoCalc with the battery inserted
Then connect the USB Type-C cable to read the battery percentage.
The battery percentage also can be retrieved via I2C communication within the UF2 program.

PicoCalc keyboard firmware updating required.

Code/picocalc_helloworld/i2ckbd/i2ckbd.c

@@ -26,13 +26,14 @@ int read_i2c_kbd() {
 
     retval = i2c_write_timeout_us(I2C_KBD_MOD, I2C_KBD_ADDR, msg, 1, false, 500000);
     if (retval == PICO_ERROR_GENERIC || retval == PICO_ERROR_TIMEOUT) {
-        printf("i2c write error\n");
+        printf("read_i2c_kbd i2c write error\n");
         return -1;
     }
 
+    sleep_ms(16);
     retval = i2c_read_timeout_us(I2C_KBD_MOD, I2C_KBD_ADDR, (unsigned char *) &buff, 2, false, 500000);
     if (retval == PICO_ERROR_GENERIC || retval == PICO_ERROR_TIMEOUT) {
-        printf("i2c read error read\n");
+        printf("read_i2c_kbd i2c read error read\n");
         return -1;
     }
 
@@ -54,4 +55,30 @@ int read_i2c_kbd() {
         return c;
     }
     return -1;
+}
+
+int read_battery() {
+    int retval;
+    uint16_t buff = 0;
+    unsigned char msg[2];
+    msg[0] = 0x0b;
+
+    if (i2c_inited == 0) return -1;
+
+    retval = i2c_write_timeout_us(I2C_KBD_MOD, I2C_KBD_ADDR, msg, 1, false, 500000);
+    if (retval == PICO_ERROR_GENERIC || retval == PICO_ERROR_TIMEOUT) {
+        printf("read_battery i2c write error\n");
+        return -1;
+    }
+    sleep_ms(16);
+    retval = i2c_read_timeout_us(I2C_KBD_MOD, I2C_KBD_ADDR, (unsigned char *) &buff, 2, false, 500000);
+    if (retval == PICO_ERROR_GENERIC || retval == PICO_ERROR_TIMEOUT) {
+        printf("read_battery i2c read error read\n");
+        return -1;
+    }
+
+    if (buff != 0) {
+        return buff;
+    }
+    return -1;
 }

Code/picocalc_helloworld/i2ckbd/i2ckbd.h

@@ -9,11 +9,12 @@
 #define I2C_KBD_SDA 6
 #define I2C_KBD_SCL 7
 
-#define I2C_KBD_SPEED  400000 // if dual i2c, then the speed of keyboard i2c should be 10khz
+#define I2C_KBD_SPEED  10000 // if dual i2c, then the speed of keyboard i2c should be 10khz
 
 #define I2C_KBD_ADDR 0x1F
 
 void init_i2c_kbd();
 int read_i2c_kbd();
+int read_battery();
 
 #endif

Code/picocalc_helloworld/main.c

@@ -204,10 +204,14 @@ void pwm_interrupt_handler() {
 }
 
 int main() {
-
-    stdio_init_all();
+    char buf[64];
     set_sys_clock_khz(133000, true);
+    stdio_init_all();
 
+    uart_init(uart0, 115200);
+
+    uart_set_format(uart0, 8, 1, UART_PARITY_NONE);  // 8-N-1
+    uart_set_fifo_enabled(uart0, false);
 
     init_i2c_kbd();
     lcd_init();
@@ -225,7 +229,17 @@ int main() {
 
     psram_spi_inst_t psram_spi = psram_spi_init_clkdiv(pio1, -1,1.0f,true);
     psram_test(&psram_spi);
+    // if we need battery information
+    // ** we should power on the picocalc only with batteries
+    // ** then plug the type c cable
+    // otherwise we won't get working battery infos
 
+    sleep_ms(2000);
+    int bat_pcnt = read_battery();
+
+    sprintf(buf,"battery percent is %d\n",bat_pcnt>>8);
+    printf(buf);
+    lcd_print_string(buf);
     while (1) {
 
         int c = lcd_getc(0);

Code/picocalc_keyboard/picocalc_keyboard.ino

@@ -42,6 +42,8 @@ uint8_t write_buffer_len = 0;
 uint8_t io_matrix[9];//for IO matrix,last bytye is the restore key(c64 only)
 uint8_t js_bits=0xff;// c64 joystick bits
 
+static int current_bat_pcnt = 0;
+
 unsigned long time_uptime_ms() { return millis(); }
 
 void lock_cb(bool caps_changed, bool num_changed) {
@@ -134,12 +136,10 @@ void receiveEvent(int howMany) {
       write_buffer[1] = reg_get_value(REG_ID_BKL);
     } break;
     case REG_ID_BAT:{
+      //Serial1.print("REG_ID_BAT getBatteryPercent:");Serial1.print(current_bat_pcnt);Serial1.println("%");
       write_buffer[0] = reg;
-      if (PMU.isBatteryConnect()) {
-        write_buffer[1] = PMU.getBatteryPercent();
-      }else{
-        write_buffer[1] = 0x00;
-      }
+      write_buffer[1] = (uint8_t)current_bat_pcnt;
+      
     }break;
     case REG_ID_KEY: {
       write_buffer[0] = fifo_count();
@@ -229,19 +229,20 @@ void printPMU() {
 }
 
 void check_pmu_int() {
-  /// 40 secs check battery percent
-
   int pcnt;
 
   if (!pmu_online) return;
-
-  if (time_uptime_ms() - run_time > 40000) {
+  
+  if (time_uptime_ms() - run_time > 20000) {
     run_time = millis();  // reset time
     pcnt = PMU.getBatteryPercent();
+    //Serial1.print("check_pmu_int:  ");Serial1.print(pcnt);Serial1.println();
     if (pcnt < 0) {  // disconnect
       pcnt = 0;
       pmu_status = 0xff;
+      current_bat_pcnt = pcnt;
     } else {  // battery connected
+      current_bat_pcnt = pcnt;
       if (PMU.isCharging()) {
         pmu_status = bitSet(pcnt, 7);
       } else {
@@ -304,11 +305,12 @@ void check_pmu_int() {
       } else {
         pmu_status = pcnt;
       }
-
+      current_bat_pcnt = pcnt;
       Serial1.println("isBatInsert");
     }
     if (PMU.isBatRemoveIrq()) {
       pmu_status = 0xff;
+      current_bat_pcnt = 0;
       Serial1.println("isBatRemove");
       stop_chg();
     }
@@ -359,6 +361,7 @@ void check_pmu_int() {
         pcnt = 0;
         pmu_status = 0xff;
       }
+      current_bat_pcnt = pcnt;
       pmu_status = bitClear(pcnt, 7);
       Serial1.println("isBatChagerDone");
       stop_chg();
@@ -369,6 +372,7 @@ void check_pmu_int() {
         pcnt = 0;
         pmu_status = 0xff;
       }
+      current_bat_pcnt = pcnt;
       pmu_status = bitSet(pcnt, 7);
       Serial1.println("isBatChagerStart");
       if(PMU.isBatteryConnect()) {
@@ -517,8 +521,7 @@ void setup() {
     // 5%  ~= 3.5V
     // 1%  ~= 3.4V
   PMU.setLowBatShutdownThreshold(1);  //This is related to the battery charging and discharging logic. If you're not sure what you're doing, please don't modify it, as it could damage the battery.
-
-
+  
   run_time = 0;
   keycb_start = 1;
   low_bat();