Devo 12s 3in1 / 4in1 RF module neat installation.

Vlady_vy - In your picture tutorial specifically for 4in1 module on the 8s a few post back, you show the nrf module trigger being attached to unused pin b3. Recently I was looking through banggood reviews on the 3in1 module and someone posted a picture of using pin b7 to trigger the nrf. It had a spot to solder to on the trace making it easier to access than b3 on the mcu. I was wondering what pin b7 was being used for and if it would be a good alternative to pin b3 when installing the 4in1. I can attach a picture for reference if you would like to see it but would rather not perpetuate bad information if its wrong

Also there appears to be larger group of unused pins to the left of b3 near the corner of the mcu. Would it be safer/easier to use one of those rather than b3 so that the target pin would be isolated on both sides by other unused pins making the job safer for a mistake with too much solder? Thanks again!

I must be wrong about the pins then. IT just looked like they were unused because I did not see traces coming off of them in the picture. I trust your judgment better than mine. Thanks for the information on pin b7. The person that posted that picture on banggood reviews reported that it worked. IT seems that using a pin to control both the nrf module and also its intended purpose of button matrix col 2 would seem like a bad idea. What do you think?

A quick question on the VCC supply on the 3 in 1 and 4 in 1 modules.

The documentation on the:

3 in 1 - VCC is 3.3V
4 in 1 - VCC is 4.5 to 8V

Reading this thread:

I read that the 4 in 1 has its own 3.3V regulator onboard to power the TX modules. (Solving the 3.3V supply issues from the stock regulator.)

I also read that the VCC to the stock CYRF6936 is greater than 3.3V as this is where the 4 in 1 gets its 4.8 to 8V from.

Now my question relates to the Devention 12S transmitter. The 12S is powered by a single cell 3.7V LiPo.

On the connection to the stock TX module is there a step up in voltage to power the stock module?

The real question is does the 4 in 1 module work on a Devo 12S given the difference in the Power Supply Voltage to the other Devo radios?

Cheers

It's a very interesting question indeed. I'll try to measure the voltage on the module in 12s. In fact, so called 3.7v battery has more than this in charged state. So maybe LDO on the module sites its job well using 3.8-4.2v to make 3.3.

I was using AMS1117 in devo 7e. I was not pleased, due to dropout, I could only use little bit of the pack and must always full charge.
4 nimh pack empty battery volt alarm could be set at 4Volt. (You may even go up to 0.9 volt cell)
Anyway I replaced for pololu step/up down 3v3 regulator. I wanted to be sure of good psu, Likely it is very easy on the module to bypass regulatro and feed it with 3v3?

CYRF6936 chip also need 3v3 vcc, possibly in devo stock module there is also small regulator to 3v3? But Is it true that devo stock module get 5Volt? I never checked.

i just installed the 4 in 1 module from banggood and when i turn on my radio missing 7105. all the other modules are working because when i try to bind to the other protocols there is no asterisk. help please.

mi mistake i got fix.

victzh wrote: It's a very interesting question indeed. I'll try to measure the voltage on the module in 12s. In fact, so called 3.7v battery has more than this in charged state. So maybe LDO on the module sites its job well using 3.8-4.2v to make 3.3.

Thanks.

3.7V is the "Nominal Voltage" of a single cell lipo. Like 7.4 for a 2s and 11.1 for a 3S etc. At 3.3V it is flat at 4.2V it is fully charged..

The connection picture from Banggood on the 4 in 1 module states the Pinouts as

Pin Function:
Name Attributes Function
CSN2500 Input CC2500 chip select signal
CSN2401 Input NRF24L01 chip select signal
CSN7105 Input A7105 chip select signal
CSN6936 Input CYRF6936 chip select signal
SCK Input SPI Interface clock signal
MOSI Input SPI Interface input from the device
MISO Output SPI Interface output from the device
VIN Input Power Source 4.5V-8V
GND Input Power Source Ground
RST6936 Input CYRF6936 chip select signal

So even at full charge the 4.2 is below the minimum 4.5 for the 4 in 1 module.

If you can measure your 12 that would be great. I will pull apart a 12S and a 10 and a 12E and an 8s and check the VCC on the standard module on all of them. We can compare notes as a second reference.

Cheers

Does any one know where else to get the 4-in-1 module apart from Banggood, they are out of stock and not expecting any with 19th November.

the only other place i know of is direct from the manufacturer through his taobao page using an intermediary site, details are in this thread a few posts back

Yeah, I've been on his site but he doesn't ship to EU/UK. Also the module shown is different to the one on Banggood, it has a dial and LED on it so I wasn't sure if it was even the same one.Thanks though, I guess all good things come to those who wait!

You should look here for the right module. If you wish I can help you get the module and ship to you. Here is the module I got from him. He now has 4 left according to the Taobao listing.

Could anyone please measure the size of the 4in1 module, thinking about using it in a small transmitter build. together with a pro-mini that should make a complete multimodule, right?

BTW. What range do you get on FrSky Receivers with the 4in1?

Thanks
Johannes

If I remember right it is the same size as the original module which I can measure tonight if no one has by then.

ajtank wrote: You should look here for the right module. If you wish I can help you get the module and ship to you. Here is the module I got from him. He now has 4 left according to the Taobao listing.

Can we read the marking on the regulator at the back?

BTW, the 1.5V drop out voltage for 1117 is for the rated current (~0.8A). Drop out voltage would be lower if the current drawn is lower.

Please see page 3 for more explanation:

focus.ti.com/download/trng/docs/seminar/...%20LDO%20dropout.pdf

If we expect it to work with 1S, we probably should use a 3V out LDO (1117-3.0) and double/tripple it up.

Anyway I wonder which LDO we have on the 4 in 1.

wasp09 it's an 1117 they use on the 4in1 also