Mer/Documentation/BME Protocol
This documentation is entirely for the purpose of implementing software gathering battery information on Nokia Internet Tablets, not alteration of battery management state.
Existing code:
- Dummy server: https://garage.maemo.org/plugins/scmsvn/viewcvs.php/dsme/trunk/adhoc/dummy_bme.c?revision=155&root=dsm&view=markup , released as LGPL 2.1. (Bug: The server shouldn't send a status word before sending the response struct.)
- Simple command-line client written based on this web page: http://bowman.infotech.monash.edu.au/~pmoulder/bme-client.c . (GPLv2+, assuming that the text on this web page is compatible with that license.)
General protocol:
- UNIX socket connection to /tmp/.bmesrv
- Client: send('BMentity')
- Server: send('\n')
After handshake:
typedef struct {
uint16 type, subtype;
} BMEHeader;
types so far (NAME, (type, subtype)):
Contents |
EM_BATTERY_INFO_REQ (0x06, 0x00)
typedef struct {
BMEHeader header;
u_int32_t flags; // Set to 0xFFFFFFFF to get all data
} BME_EM_BATTERY_INFO_Req;
struct emsg_battery_info_reply {
uint32 a;
uint32 flags;
uint16 c;
uint16 d;
uint16 temp; // Battery temperature measured in Kelvin
uint16 f;
uint16 g;
uint16 h;
uint16 i;
uint16 j;
uint16 k;
uint16 l;
};
Some BULK0 message (0x42, 0x00)
typedef struct {
BMEHeader header;
u_int32_t flags; // Set to 0xFFFFFFFF to get all data
} BME_EM_BULK_Req;
struct emsg_bme_bulk_reply {
uint32 unknown1;
uint32 unknown2;
uint32 unknown3;
uint16 sw_status; // Battery monitor SW status
uint16 instaneous_battery_voltage; // Instantaneous battery voltage (mV)
uint16 // Remaining standby time to battery low (mins)
uint16 unknown4;
uint16 unknown5;
uint16 unknown6;
uint16 // Battery monitor check voltage (mV)
uint16 // Battery low warning interval counter
uint16 // Double median filtered battery voltage
uint16 // Initial battery monitor voltage (mV)
uint16 // Time per battery bar (mins)
uint16 // DMF voltage sampled at first battery low (mV)
uint32 // Average phone current (uA)
uint16 // Most recent battery charge condition (mAh)
uint16 // Lowest TX-Off voltage (mV)
uint16 // Lowest TX-On voltage (mV)
uint16 // Largest TX-Off/On voltage difference (mV)
uint8 // Battery bar level log mask
uint8 // Previous battery bar level
uint8 // Battery low reason
uint8 // CS state information
uint16 // Number of battery bars
uint16 // Battery type
uint16 // Temperature, in kelvin
uint16 // Battery capacity
uint16 // Battery impedance (mOhm)
uint16 // Present value of v_bat_full_level
uint16 // Present value of v_bat_low_ths_mv
uint16 unknown7;
uint16 unknown8;
uint16 unknown9;
uint16 // Load current estimated by Batmon4 (uA)
uint16 unknown10;
};
Some BULK1 message (0x43, 0x00)
typedef struct {
BMEHeader header;
u_int32_t flags; // Set to 0xFFFFFFFF to get all data
} BME_EM_BULK1_Req;
struct emsg_bme_bulk1_reply {
uint32 unknown1;
uint32 unknown2;
uint32 unknown3;
uint16 // Elapsed model time (min)
uint16 // Tx-Off battery voltage (mV)
uint16 // Tx-On battery voltage (mV)
uint8 // Battery power state
uint8 // Batmon4 internal flags2
uint8 // Batmon4 internal flags3
uint8 // Charging method
uint16 // Present Phi value (mV)
uint16 // Present Delta Phi value (mV)
uint8 // Charging mode
uint8 // Previous charging mode
uint8 // Charger type
uint8 // Previous charger type
uint16 // Instantaneous battery voltage (mV)
uint8 // Number of charger checks (0-9) ?
uint8 // Charger recognition state
uint16 unknown4;
uint16 // Instantaneous charger current (mA)
uint16 unknown5;
uint16 // Charging time (min)
uint16 // Average Vchar (mV)
uint16 // Equivalent DC charger current (mA)
uint8 // Battery full flag (0 or 1)
uint8 // HW Cha PWM value L ??
uint8 // Cha PWM value L ??
uint8 unknown6;
uint16 // Open switch battery voltage (mV)
uint16 // Closed switch battery voltage (mV)
uint16 unknown7;
};
Some BULK2 message (0x44, 0x00)
typedef struct {
BMEHeader header;
u_int32_t flags; // Set to 0xFFFFFFFF to get all data
} BME_EM_BULK2_Req;
struct emsg_bme_bulk2_reply {
uint32 unknown1;
uint32 unknown2;
uint32 unknown3;
uint16 // Conf. battery footprint
uint16 // Conf. minimum standby current (mA)
uint16 // Conf. Batmon battery low voltage (Safety level)
uint16 // Conf. Batmon battery low voltage (Empty)
uint16 // Configured number of battery bars
uint16 unknown4;
};