[chbot] FW: Power for 12v / 5v solutions.

Daniel Powell danielvieway at hotmail.com
Thu Apr 22 07:45:10 BST 2021

Admin, edited with smaller image size.

Thankyou gents for the advice. I've already got a range of buck converters. I just wondered if there was a tidier solution in a "dual output voltage" buck converter, or some form of split voltage single buck.... Or if I was barking up the wrong tree.

The Ryobi battery pack is "intelligent", will shut down prior to 18650 damage. It's a handy platform given I run all the race car pit equipment on said batteries.

Should there be interest I'll certainly show off the datalogging solution, however the dash is only part of said solution.

As I have a broadcast, connectionless, data stream via ESPNow it gives me the ability receive the data via any number of end devices. An in-car dash using several Atoms and 7 segs has been benched along with a long-range wireless solution using a TTGo T Beam and LoRa. The receiving end of which hosts a standard WiFi AP and an async web server.

I've also been playing with the proprietary ESP Long Range Wifi. Which promises WiFi range of significant distances.

I will however warn the group that I've no background in either component electronics or coding (which I've bludgeoned together with the rudimentary Arduino IDE)....and it's forehead flattening (through thumping on desk for hours on end) lack of debugging....PlatformIO here I come.


From: Chchrobotics <chchrobotics-bounces at lists.ourshack.com<mailto:chchrobotics-bounces at lists.ourshack.com>> On Behalf Of Andrew Errington
Sent: Thursday, 22 April 2021 4:36 PM
To: Christchurch Robotics <chchrobotics at lists.ourshack.com<mailto:chchrobotics at lists.ourshack.com>>
Subject: Re: [chbot] Power for 12v / 5v solutions.

Hello Daniel,

I hope you get a range of replies to help you choose, however, these days knowledge doesn't count for quite so much since everyone buys the same modules from China.

A very common one is the LM2596, which appears in various guises. Here's one from a local supplier, but there are several versions from various places:


That module is available in (at least) two physical sizes with different PCB dimensions and different hole spacings. Don't ask me how I know.

There are also versions available with fixed output instead of the adjustable pot. I have had several in the field (literally) powering Arduinos and other modules for months with no problems.

Here's an article about the regulator itself, but you don't need to know how it works in order to use it:


You do need to know the parameters of the rest of your system though, however I suspect you will not need 3A current handling, and based on your requirements you will not be generating much waste heat. What is the current requirement of the dash?

If you want to bling up your rig then there are regulator modules with 7-segment displays for voltage and current, but they use power themselves so might reduce your battery life.

Finally, I don't know about Ryobi battery packs, but you should check what they do when they are getting low. If they keep going until they're literally flat it's bad for the cells, but it's quite likely that there is a low-voltage cutoff inside the pack so the power will just stop.

Aside from that, the project sounds really interesting. If you can bring it (or part of it) along sometime I'm sure it will be well received. Or if you want to arrange a private viewing off-list then please include me in your invite.


On Thu, 22 Apr 2021, 15:34 Daniel Powell, <danielvieway at hotmail.com<mailto:danielvieway at hotmail.com>> wrote:
I've been playing with a remote battery powered dash for my race car based on a Mazda RX8 dash and ESPNow.

I've successfully prototyped the unit using a couple of M5stack Atom's and external CAN Bus transceivers.

The Atom is powered via USB and the dash (12v) via an external 240v power adaptor.

I'm not looking to produce my own board (I'm not quite of that skill set yet) however want to integrate the unit into something somewhat more portable using a single Ryobi 18v battery as a power source. I was thinking two buck converters, one for 12v for the dash (thinking 18v might be a little much for the dash) and a second for the 5v logic.

Would appreciate advice from those who are considerably more knowledgeable and exposed to modular power supplies than I am and could possibly point me in the direction of a more suitable or tidier solution.


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