Hi there, is there any plan to disclose RAK3172(LP)-SiP schematics and BOM ?
I don’t really see any reason not to do that, as I doubt there’s much differences from ST’s reference designs (as Carl Rowan pointed out on a LinkedIn post recently:There is no reason why schematic designs of modular hardware platform like RAKwireless (IoT focused) WisBlock should be closed-source.).
As firmware developer, it is important to know for example RF-switch and TCXO part numbers and connections.
Hi @TheDude ,
There is no plan to open the internals of RAK3172LP-SiP.
But for WisBlock, which is a modular hardware platform, it should be open-source since people build on top of it.
However, for the RAK3172LP-SiP, we provide the radio files for the RFswitch and TCXO enable pins that would be useful for custom FW development. This approach works (even we do not fully open the hardware) because RAK3172LP-SiP came to life from a request of a customer who needs the low power RF output path of the STM32WL.
Hi Carl,
so just to clarify and for the sake of having the information stated in one place for people that do need to control the RF-frontend by themselves:
For both RAK3172-SiP and RAK3172LP-SiP:
- The RF-switch is a SPDT controlled by PA0 and PA1 (no other IO for Power)
- PA0=1 and PA1=0 for Rx path
- PA0=0 and PA1=1 for Tx path (LP or HP depending on SiP version)
- The TCXO is powered by PB0-VDD_TCXO and should be setup to 3v0.
Then a last question:
Does the latter point implies that the SiP is not expected to work with VDDRF below 3v0 (even 3v2 as PB0 is an LDO output) ?
hello all,
last question from @TheDude is very interesting, but it is still unanswered.
Thanks also @TheDude for summarizing all the updates about RF Front End.
@carlrowan
Is this the reference of TCXO used on both RAK3172-SiP and RAK3172LP-SiP ?
REF TCXO: NT2016SA-32M-END4263A
I have found this on other forums.
Minimum Voltage of this TCXO is 1.8VDC , I have done some tests with TCXO_CTRL_1_8V TCXO_CTRL_2_2V (other values are available on radio_driver.h) and it works. I didn’t do further tests at cold temperature to see the stability.
If RAK wireless can display all these information on their datasheet, you will get more industrial customers working on STM32CubeIDE .
Thanks again.
damon
Welcom back to RAK forum @damon .
I am checking now with our team the TCXO used on both models. I am not sure where you get the specific TCXO model but I have to confirm yet if that is correct.
Hi @damon ,
This is the TCXO used - Epson +105 ℃ & ST compatible TCXO TG2016SLN | News | Epson Crystal Device
This is different on the one you posted.
hello @carlrowan ,
thank you very much ,
the other one comes from this topic but it’s related to RAK3172-T and not the SIP version:
This TCXO from EPSON comes with different suffix ( with VCC @1.8VDC or 2.8VDC or 3VDC or 3.3VDC , page 2 of EPSON specs)
can you provide the exact reference ? then we will know the minimum voltage we can use to power it.
thanks again @carlrowan ,
damon