I have two queries for anyone who can help me,
1)What is the maximum payload for US915_HYBRID, SF7, 125kHz BW for LoRa?
2)I need an extra UART on stm32l072cz LoRa discovery board. Can anyone help with this.
Thanks in advance
You can look that up in the LoRa specifications; specifically, the Regional Parameters document.
I need an extra UART on stm32l072cz LoRa discovery board
If there's not sufficient on-board, then you have the standard two possibilities:
The radio supports up to 255 bytes when suitable configured, by default I think it is 64 bytes, so consider ways to packetize data, or compress current data.
USART options are limited
PA13/PA14 LPUART1 (SWD)
PA0 USART4_TX (DEBUG TELEMETRY)
Why am I not able to use PB6/PB7 and PA9/PA10 togetherly??
It is important that you learn to read the board schematic, and the chip datasheet.
Look at the B-L072Z-LRWAN1 schematic:
So, if you want to use them for UART comms, you'll have to disconnect those LEDs.
The board's User Manual (as well as the schematic) tell you how to do that.
Look at Table 16. STM32L072xxx pin definition in the Datasheet:
So you could use PB6/PA10 or PA9/PB7, subject to pin availability on the board - see above.
Neil.Andrew wrote:if you want to use [PB6,7] for UART comms, you'll have to disconnect those LEDs.
if you want to use [PB6,7] for UART comms, you'll have to disconnect those LEDs.
and, of course, disable any software that tries to use them as LEDs!
I don't think LEDs will be a problem. My solution to this is initializing PA9/10 when I need them and using PB6/7 when I need them, what do you think, will this work?
You haven't said what you're trying to achieve by that - so impossible to say whether it would work or not!
I have connected a device1 to PORTA 9/10 and need it to get data1, while
I have connected a device2 to PORTB 6/7 and need it to get data2.
While getting data1, I shall initialize AF6-USART1 on PORTA 9/10 and de-initialize after my work is done, and
While getting data2, I shall initialize AF0-USART1 on PORTB 6/7 and de-initialize after my work is done.
I hope it is clear
So you are effectively making a "changeover" switch to route the two devices (one at a time) to the one UART.
In principle, that should work.
In practice, it assumes that nothing (important) comes from the "disconnected" device while you're not listening to it...
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