Hi, I have a problem configuring the PPP Modem correctly and I'm not quite sure what i'm missing here.
I'm running the code on a custom board. We are using nRF52832 to talk to Telit ML865G1 modem over UART and we don't have any HW control pins implemented so it's pretty much just RX&TX.
Everything seems to be functioning correctly but the response from modem is not being received by nRF52.
- modem is powered and activated.
- UART get correctly initialized
- modem list (shell) lists the modem on the correct UART Iface
- I scoped the UART lines and the AT command that's called by gsm_ppp_start->gsm_configure gets sent correctly with correct baud rate
- The correct AT OK response is also generated by the modem and is detected both by a scope & a USB to serial converter
- we also have an NRF5 sdk based solution that is able to successfully comunicate with the modem on the same board
however, with net_dbg logging enabled the modem generates the following error:
modem_gsm.gsm_configure: modem not ready -116
My suspicion is that the configurations i'm trying to run this in doesn't work unless RTS/CTS pins are implemented. Could you suggest something to troubleshoot this further or some other configuration combo that i'm missing here.
Code, board definitions and configuration provided below.
Here's a snippet of our custom board.dts:
&uart0 {
status = "okay";
compatible = "nordic,nrf-uarte";
current-speed = <9600>;
tx-pin = <6>;
rx-pin = <8>;
label = "HTS_UART_0";
rts-pin = <0xFFFFFFFF>;
cts-pin = <0xFFFFFFFF>;
};
I'm also using an additional overlay file with the following contents:
&uart0 {
status = "okay";
current-speed = <115200>;
/delete-property/ rts-pin;
/delete-property/ cts-pin;
gsm: gsm-modem {
compatible = "zephyr,gsm-ppp";
label = "gsm_ppp";
status = "okay";
};
};
Here's the relevant bits of prj.conf:
CONFIG_UART_ASYNC_API=y CONFIG_UART_0_ASYNC=y CONFIG_UART_0_INTERRUPT_DRIVEN=n CONFIG_MODEM=y CONFIG_MODEM_GSM_PPP=y CONFIG_NET_DRIVERS=y CONFIG_NET_PPP=y CONFIG_NET_L2_PPP=y CONFIG_NET_NATIVE=y CONFIG_NETWORKING=y CONFIG_GSM_PPP_AUTOSTART=n CONFIG_NET_PPP_ASYNC_UART=y
Here's the code itself:
const struct device *uart_dev = DEVICE_DT_GET(DT_BUS(DT_INST(0, zephyr_gsm_ppp)));
gsm_dev = DEVICE_DT_GET(DT_INST(0, zephyr_gsm_ppp));
LOG_INF("Board '%s' APN '%s' UART '%s' device %p (%s)",
CONFIG_BOARD, CONFIG_MODEM_GSM_APN,
DT_BUS_LABEL(DT_INST(0, zephyr_gsm_ppp)), uart_dev,
gsm_dev->name);
net_mgmt_init_event_callback(&mgmt_cb, event_handler,
NET_EVENT_L4_CONNECTED |
NET_EVENT_L4_DISCONNECTED);
net_mgmt_add_event_callback(&mgmt_cb);
LOG_INF("Modem Device INIT");
gsm_ppp_start(gsm_dev);
It's pretty much a verbatim copy of net/gsm_modem example.
