LiPo Battery Charger

[RocketDestroyer]

I have an Adafruit ESP32-S3 Reverse TFT Feather board and have discovered that it can be used out of the box as a nice battery charger for my single cell LiPo batteries. You don't even have to write any software if you don't want to. It comes with demo software that shows the battery voltage and charge percentage. Jus plug a battery into the JST connector and it will boot up and show the battery status. Plug it into a USB port and it will switch over to the charging mode and you can monitor the progress. It will stop charging when the charge is complete so no worries about over charging the battery. All this for just under $25.

 

[waltr]

Nice.
I really do like Adafruit stuff. Well thought out and nicely designed.

 

[kjhambrick]

@RocketDestroyer --

Very Kool.

I can't tell from the adafruit site ...

Is the Adafruit ESP32-S3 Reverse TFT Feather board ready to use as is or is it a kit ?

And ...

Do you know anything about the built-in 'time of flight distance measurements' in the device ?

Thanks for the info

-- kjh( who's vision is fading and my soldering skills long ago went the way of the Dodo )

 

[darrenf]

@RocketDestroyer --

Very Kool.

I can't tell from the adafruit site ...

Is the Adafruit ESP32-S3 Reverse TFT Feather board ready to use as is or is it a kit ?

And ...

Do you know anything about the built-in 'time of flight distance measurements' in the device ?

Thanks for the info

-- kjh( who's vision is fading and my soldering skills long ago went the way of the Dodo )

From their site...

Kits​

What is included in a kit?

Kits come with all the parts listed on the product page, including a custom printed circuit board and any preprogrammed chips. Batteries are not included unless indicated otherwise. Please read each product page carefully. Tools necessary for assembly, such as soldering irons, solder, pliers, etc. are generally not included.

I don't think I have the skill/tools to build this kit, can you sell me a prebuilt kit? How much will it cost for me to buy a fully built device?

We are only able to offer the kits and items as they are shown on the site. We are not able to offer any custom or pre-assembled products. Because of requests like this, we created a free jobs boards to connect those needing assistance with our talented community. This has worked out for many people - helping top businesses find staff and services, and helping makers showcase their skills: http://www.adafruit.com/jobs/

 

[kjhambrick]

Thanks @darrenf.

I thought that's what I was reading ...

-- kjh

 

[RocketDestroyer]

The board came assembled. The only thing I had to do to use it was plug in one of my LiPo batteries to see the state of charge and then plug in a USB cable to start the charging process. It really is as simple as take it out of the box and use it.

Adafruit also sell the ESP32-S3 TFT feather as opposed to the reverse feather that I pictured. The difference beside the display on the front of the board is that the charging LED and display are both on the same side. If I were buying one just for charging, I would get that one. As it was, I already had the reverse feather so I used it.

Adafruit ESP32-S3 TFT Feather - 4MB Flash, 2MB PSRAM, STEMMA QT​

Product ID: 5483

 

[kjhambrick]

Woo Hoo @RocketDestroyer !

Hmmm ... Sounds like I might want the ESP32-S3 TFT Feather where the visuals are all on one side.

OTOH, the Adafruit ESP32-S2 Reverse TFT Feather ( Product ID: 5345 ) that you have seems ready to put in a box and it has the three push buttons and the built-in 'time of flight distance measurements' ( whatever that is )

I like the full color display with the battery status all for $25 on either version !

I'll read about them before I ask any more Qs but either board sounds Kool !

Thanks again @RocketDestroyer !

-- kjh

 

[RocketDestroyer]

"Do you know anything about the built-in 'time of flight distance measurements' in the device ?"

No, sorry I don't. I'm guessing that you would need some ultrasonic sensors and to write some code to make that work.

 

[RocketDestroyer]

Okay, a quick search of the Adafruit site came up with this.

https://www.adafruit.com/product/5396

It's a sensor that plugs into the TFT Feather board and will do time of flight distance measurements. There appears to be demo code available for the sensor.

 

[darrenf]

The board came assembled. The only thing I had to do to use it was plug in one of my LiPo batteries to see the state of charge and then plug in a USB cable to start the charging process. It really is as simple as take it out of the box and use it.

Adafruit also sell the ESP32-S3 TFT feather as opposed to the reverse feather that I pictured. The difference beside the display on the front of the board is that the charging LED and display are both on the same side. If I were buying one just for charging, I would get that one. As it was, I already had the reverse feather so I used it.

Adafruit ESP32-S3 TFT Feather - 4MB Flash, 2MB PSRAM, STEMMA QT​

Product ID: 5483

Well that's a pleasant surprise!

 

[kjhambrick]

Okay, a quick search of the Adafruit site came up with this.

https://www.adafruit.com/product/5396

It's a sensor that plugs into the TFT Feather board and will do time of flight distance measurements. There appears to be demo code available for the sensor.

@RocketDestroyer --

I've been searching the site -- I believe It is a LIDAR sensor that can measure how long it takes a laser beam to travel to an object then reflect back to the gadget.

Here is one: Adafruit VL53L0X Time of Flight Micro-LIDAR Distance Sensor Breakout

The Max range appears to be 2 meters max ( under perfect conditions ).

So ... how could I use that in a rocket ???

-- kjh

 

[kjhambrick]

Well that's a pleasant surprise!

@darrenf

Yes it is. I want to learn more about these gadgets ...

I had no idea how far IoT and gadgetry had progressed in my absence.

-- kjh( just call me Rip ( van Winkle ) )

 

[waltr]

"Do you know anything about the built-in 'time of flight distance measurements' in the device ?"

No, sorry I don't. I'm guessing that you would need some ultrasonic sensors and to write some code to make that work.

This is a feature in the ESP32-S3 module. It actual times the round trip of a 'beacon' packet to another ESP32_S3 and back using an internal pico-second counter.

Search and look in the documents for the ESP32-S3 from ESPxpressif.

 

[kjhambrick]

This is a feature in the ESP32-S3 module. It actual times the round trip of a 'beacon' packet to another ESP32_S3 and back using an internal pico-second counter.

Search and look in the documents for the ESP32-S3 from ESPxpressif.

Now that makes more sense than a laser beam !

These devices calculate distances by the time it takes for network packet round trips

Adafruit ESP32-S3 Feather > Overview

Thanks @waltr !

-- kjh( boy, do I have a lot to ponder and learn )

EDIT: I've been reading about Bluetooth ( BT ) -vs- Bluetooth Low Energy ( BLE ) ... 'time of flight distance measurement' appears to be a built-in feature of BLE if you've got the infrastructure and software in place ...

 

[waltr]

I was looking into this 'Time of Flight' feature for a location beacon to find rockets in corn fields.
A directional antenna (RDF) would give direction and the ToF the distance.
Did buy some ESP32-S3 modules but these Require Windows 10 or higher to have USB driver that supports programming. Also, there was very little info on how to use this feature from ESPxpressif at the time.

 

[RocketDestroyer]

I came across another ESP32 product that just screams rocketry projects. I found a youtube channel that had turned an M5StickC+ into a LiPo charger.



So of course I had to get one and try it out. I did make some modifications to his display screen to better suit my needs but I am pleased with the results.



This charger allows you to set the charging current where with the previous unit the the charging current was fixed. It will also time how long the charger has been running , the charger temperature (not the battery), the battery voltage and the percent of charge. As with the first unit, it will stop charging when the battery is full. It is also possible to change the display brightness. Since it has a case it seems like it would survive better in the rocket box that the unboxed unit I worked with earlier.

The ESP32 device can be easily programmed in Arduino for those so inclined.

This one requires some rather delicate work to modify the M5 as outlined in the youtube video linked above. Rather than use the pins on the unit, I permanently soldered in a JST 2 pin male header cable inside and drilled a small hole in the case for the header leads to pass through. If you do disassemble the unit to make one of these, be VERY VERY gentle with the display. The slightest pressure on the case is enough to destroy the display. I killed one display putting the case together and found this out the hard way. I didn't have the display exactly aligned in the case and tightening the screws was enough to kill it.

The M5StickC+ also has a built IMU. Maybe someone smarter than me could program it to record the rocket's altitude and other parameters? The bigger question would be if the display is robust enough to fly on the rocket.