Hello,
I’m testing the LC76G PA module and everything is working fine on the UART interface, but I need to use the I2C interface and I can’t yet get it to work. Is there any special firmware for the I2C support?
This is the response for the firmware version I have:
$PQTMVER,MODULE_LC76GPANR12A01S,2023/02/13,10:41:57*61
After the module is powered, the module also responds this (which isn’t defined in the GNSS Protocol Specification):
$PAIR021,AG3352Q_V2.3.0.AG3352_20230213,S,N,2b31f59,2209141904,d32ef91c,2209
141902,571d3e7,2209141904,-15.48,-15.48,-14.02,-15.48,0,1,##,0,0*34
Thanks.
I’ve done more tests and noticed that after powering the device and releasing the reset line, the module generates a pulse on the SDA line, is it normal?
They have an application note on it. (https://www.quectel.com/download_file/54428) “Quectel_LC26GABLC76G_Series_I2C_Application_Note_V1.0.pdf” However, I have been running into issues as well.
I finally could get the module to work through I2C. What kind of issues are you having?
If I communicate to any other devices on the I2C bus subsequent communications to the LC76G result in errors.
// start write to LC76G
[DBG][I2Cc]: I2CCOM_transferTimeout WRITE → 0x4 0x0 0x51 0xaa 0x4 0x0 0x0 0x0
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x50 WrCnt:8 RdCnt:0 st:0 << GOOD
// buffer space and get error
[DBG][I2Cc]: I2CCOM_transferTimeout READ → 0x0 0x0 0x0 0x0
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x54 WrCnt:0 RdCnt:4 st:-5 << ADDRESS NACK ERROR
// keep going, say we will write 0 bytes
[DBG][I2Cc]: I2CCOM_transferTimeout WRITE → 0x0 0x10 0x53 0xaa 0x0 0x0 0x0 0x0
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x50 WrCnt:8 RdCnt:0 st:0
// get another error, this time as we send a write with no data
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x58 WrCnt:0 RdCnt:0 st:-11
/* RETRY */
// retry write to LG76G, all works
[DBG][I2Cc]: I2CCOM_transferTimeout WRITE → 0x4 0x0 0x51 0xaa 0x4 0x0 0x0 0x0
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x50 WrCnt:8 RdCnt:0 st:0
[DBG][I2Cc]: I2CCOM_transferTimeout READ → 0x0 0x10 0x0 0x0
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x54 WrCnt:0 RdCnt:4 st:0
[DBG][I2Cc]: I2CCOM_transferTimeout WRITE → 0x0 0x10 0x53 0xaa 0x46 0x0 0x0 0x0
[DBG][I2Cc]: I2CCOM_transferTimeout timeout:10ms addr:0x50 WrCnt:8 RdCnt:0 st:0
If I retry any sooner, I get the same errors.
I can send/receive PAIR commands but only occasionally get NMEA commands. Have you run across this?