Merge branch 'rahix/low-bat-disable' into 'master'

Add config option to disable low battery check

Closes #227

See merge request !464

Documentation/card10-cfg.rst

@@ -62,4 +62,6 @@ Option name        Type       Description
 ``bsec_debug``     Boolean    Turn on debug output of the BSEC system. Prints each meaurement on the console.
 ------------------ ---------- -----------
 ``bsec_offset``    Integer    Temperature offset in .1 K. Example: Set to `-14` if temperature reads 1.4 "C" to high. Default: -2.2 K (appropriate for a card10 without a case, connected to USB and with BLE active in vertical orientation).
+------------------ ---------- -----------
+``battery_check``  Boolean    Whether the low battery check should be enabled (default ``true``).  **Warning**: Do not use this unless you know what you're doing.  This option is only meant to be used on devices with a broken PMIC ADMUX connection.
 ================== ========== ===========

epicardium/modules/pmic.c

 #include "epicardium.h"
 #include "modules/modules.h"
 #include "modules/log.h"
+#include "modules/config.h"
 
 #include "card10.h"
 #include "pmic.h"
@@ -173,6 +174,30 @@ static void pmic_check_battery()
 	float u_batt;
 	int res;
 
+	/**
+	 * 0 = uncertain, ask config
+	 * 1 = disabled
+	 * 2 = enabled
+	 */
+	static int pmic_do_battery_check = 0;
+
+	if (pmic_do_battery_check == 0) {
+		if (config_get_boolean_with_default("battery_check", true)) {
+			pmic_do_battery_check = 2;
+		} else {
+			pmic_do_battery_check = 1;
+			LOG_WARN(
+				"pmic",
+				"Battery check was disabled by config!"
+			);
+		}
+	}
+
+	if (pmic_do_battery_check == 1) {
+		/* Disabled, ignore */
+		return;
+	}
+
 	res = pmic_read_amux(PMIC_AMUX_BATT_U, &u_batt);
 	if (res < 0) {
 		LOG_ERR("pmic",