QC 3.0 DIY Solar panel.

One of the biggest problem today about the solar panels is the part after the solar cells, so the converter/ regulator. I wanted to write that for have the best performance with the solar cells for a smartphone / battery.

What do you need:

Total Cost (with 3 Solar Panel) = 26.50€

If you don’t have wires & soldering parts:


I choose to use a Cigarette Lighter Socket + QC Charger because at the moment we can’t find QC 3.0 modules, we find them only in the Car chargers.



So lets go

Part 1

Create holes, it’s just for attach the 3 solar panels



Part 2

Solder the panel, for increase the voltage like here, we have to connect like that:

(-) panel1 (+) —— (-) panel2 (+) —– (-) panel3 (+)

if you want to increase only the current you have to connect the (-) with the (-) and the (+) with the (+). But voltage will stay at 5v so the QC 3.0 will not work.




Part 3

Solder the (-) and (+) to the cigarette socket.




Part 4

Test it !

I use the new Xiaomi 20 000mAh power bank 2 (QC 3.0) with a low capacity (2/4 bar).



Around 10W !

When i made that picture the sun started to drew low, it was 20h14 and the panels were not super clean there was a little of dust on them. 20h14 is bad for the solar power, so it’s a really good result!

You can add more power by adding a solar panel in parrallele for exemple so you will need 6 panels (because we have to add a second panel for the 3 or the parrallel system will not works). But the QC is limited to 1.5A at 12v so it’s overpowered.

60Ah DIY Power Bank for 50€

I’ve build today a 60Ah power bank with 12x 26650 Cells, they are really interesting for price/wh compared to the normal 18650, i paid them less than 4€ for 5 000 mAh cells (18wH), the bad side is the weight, more important than the best 18650 cells.

  • For the 26650 for each gram there is 52,4 mAh
  • For the 18650 (Panasonic 18650B 3500mAh), for each gram there is 73 mAh.

But the discharge rate is really good, it can handle 20A, and at 15A the capacity stay around 5Ah !

Review and tests of the Liitokal 26650 5,000mAh: link

So i think if you are looking for a portable(or not) power bank it’s surly the best choice, i will personaly use it with 4x5w solar panels, and i plan to add more cells in the futur for increase the capacity and power.

For the moment i use it with a 3S BMS 25A ( HX-3S-FL25A ):


AliExpress Link

Be careful with this BMS the B2(and not the B1) must be connected after the B+ ! Like here:


It’s limited 25A but because there are 12 Cells it can go up to 80A for continuous discharge and even up to 120A but the capacity will descrease to 3,5Ah for each cell. So it can produce around 888w(80A) and max 1322w (120A).

The Cells are sold around 24€ for 6 Cells, i got them for 22€ so with the bms it’s less than 50€.


AliExpress Link

If you want to use holders like me, they are really expensive but the quality is good(we also find the same one for the 18650 cheaper but I think it’s because the 18650 are very popular)


AliExpress Link

We find also this one cheaper (so 1€ for 2 holder):


AliExpress Link

More about the A20 Plus (Pictures of the final product)


I found more info about the new A20, apparently it was available on taobao but idk why we can’t buy it at the moment, here is the link: https://world.taobao.com/item/537201526509.htm?fromSite=main&spm=a1z10.1-c.w4004-6565671699.4.OdxtAG

Important points:

  • Esp8285 for the wifi
  • No video mode available(there is an AT command for that)
  • 12-15$
  • Compatible with OV7670,GC0308,GC0328,GC0309 cameras (0.3M)
  • Flash


And we have a picture:




So there is two information:

It’s surly the biggest Ax board( and maybe there is also an UART ?)

The price: it’s very close to the A6C board for the seller, the AC6 cost 7,49$ and the A20 7,49$ (50Y and 49Y) so it will be surly around 12-13$

They added also two leds surly for the flash, in the A6C AT Commands we can activate it thx to the Camera parameters commands.


They also made an android app for use the A20Plus camera, here some pictures:


I found the Application and explanation here: http://pan.baidu.com/s/1o7UleBo#path=%252FGPRS%25E6%25A8%25A1%25E5%259D%2597%25E8%25B5%2584%25E6%2596%2599

You can also go to the online doc here, i found the last pictures here and they explain the code(in chinese): http://www.showdoc.cc/5627?page_id=37300

The first code is: 123456

We can find more info about the code here, but i can’t download his zip because we need to pay for it! : http://www.itdadao.com/articles/c15a342329p0.html

I found the biggest part of these informations on this page:


Pinout and other pictures of my previous post: https://raymondtunning.wordpress.com/2016/09/08/a20-the-new-gprsgsm-product/

Details of the A6C(like the A20 with no wifi), At commands for control the camera, demo etc: https://raymondtunning.wordpress.com/2016/09/08/best-wireless-cam-solution-a6c/

The AI-Thinker Ax “program”

I’ve discovered with this page: http://www.aliexpress.com/item/GPRS-module-GSM-module-A6C-SMS-Speech-board-minimum-system-board-A6C-adapter-plate-A6C-module/32709458659.html?spm=2114.30010308.3.116.Fp9BF9&ws_ab_test=searchweb201556_0,searchweb201602_2_10057_10056_10065_10068_10055_10054_10069_10059_10058_10073_10017_10072_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_4&btsid=042d14e1-ba67-412b-bd4b-ac37c6d9666e that AI-thinker made a page for test the A6/A6C/A7.

But the negative point is it’s in chinese… it’s really not easy to understand but it’s still a great idea:





I made a pdf copy if the link is dead(it’s only for the A6C):



Best Wireless Cam solution : A6C ?



I’ve discovered the A7, an anwsome solution for have GPS and GPRS in the same chip thx to the great Andreas Spiess youtube channel:

But he he did not talk about the A6C module, maybe because the module was not annonced at this moment, let’s me tell you the avantages of this module:

  • Size: If you know the others cam solutions for the arduino and tiny devices, you surly know the ArduCam, and it’s a BIG module because the Arduino can’t be connected directly to the Camera or we need a lot connections so a big module like this one:

    The A6C has the same cam(OV7670) but it’s more smaller and we need just 2new connection for the Arduino, RX/TX just for the cam!a6c-module-03

  • Price: Surly the important point because we can have smaller, better résolution, better gprs etc but much more expensive! I think for exemple to the Raspberry pi Zero and his high definition camera, normaly they cost around 25$ and with a good Gsm/gprs module around 50$. I also wanted to do a wireless camera with a Esp8266, it’s a cheap module but the cameras are really expensive, like this one: http://www.uctronics.com/arducam-2mp-v2-mini-camera-shield-with-esp8266-nano-esp-12f-evaluation-kits.html and i didn’t find a solution above 25$…  But with the high price we have also better résolution, 2M against 0.3M max for the A6C but personaly i don’t know what can happen to a wireless module so i prefer a cheap one which do the basic job. His price is around 12$, with the camera which cost normaly around 3.5$. But the module is likely to cost less in the future because i’ve found only few sellers.


I think there is no better deal for a wireless Cam module at this moment, 12$ is a great price and it can be really interesting for the makers community which don’t want to spend more than 15$ for send a picture through a wireless module.




AT Commands

AT+CAMSTART         (Start the Cam and choose the resolution)

  • AT+CAMSTART=0       (QVGA: 320×240)

  • AT+CAMSTART=1         (VGA: 640×480)

  • AT+CAMSTART=2        (QQVGA: 160×120)


AT+CAMSTOP       (Stop the camera)

AT+CAMCAP         (Take a picture, the default format is .JPG)

AT+CAMRD          (Read the content of the picture)

  • AT+CAMRD=fromaddr,toaddr;


AT+CAMREC (Not available for the moment)

AT+CAMCFG (Camera configuration)

  • AT+CAMCFG=mode,param

This is pure Reverso traduction because i don’t understand what they really say(in chinese):

  • 0 indicates that the flash mode, the parameter is 0, Off, 1, 2 Open Automatically
  • 1 indicates whether a night market, the parameter is 0, no night vision, 1 open the night vision
  • 2 indicates that the image quality, parameters 0,1,2 //7,10,14,20
  • 3 indicates that the image is rotated, the parameter is 0, indicating that will not rotate 1 rotate 90 degrees, 2 rotate 180 degree and 3 rotate 270 degree
  • 4 The exposure parameters -2,-1,0,1,2
  • 5 brightness, parameters -2,-1,0,1,2
  • 6 white balance, parameter 0-auto,1-daylight,2- daylight (0x08),3-cloudy(0x09),4- (0x0a) tungsten lamps
  • 7 contrast parameters 1-5;


Interesting Docs:


a6_a7_a6c_datasheet-en (Page 15 for the A6C)

AT Commands(in chinese)

ai-thinker_a6_a7_a6c_at_v1-02 (Page 171 for the A6C)


Few interesting links:

Module in AliExpress:   http://www.aliexpress.com/item/Free-Shipping-Camera-GPRS-module-GSM-module-A6C-text-voice-development-board-the-minimum-system-board/32713287145.html?spm=2114.30010308.3.2.ywlegh&ws_ab_test=searchweb201556_0,searchweb201602_2_10057_10056_10065_10068_10055_10054_10069_10059_10058_10073_10017_10072_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_4&btsid=e228f014-6743-4419-9334-4f7f6f0fad21

Doc: http://www.electrodragon.com/w/GSM_GPRS_A6_Module

How to use it: http://www.electrodragon.com/w/File:A6C_Cam_Capture.zip  (You can open with Google Chrome or IE)

Doc from IA-Thinker(there is a part in chinese :/) : http://wiki.ai-thinker.com/lib/exe/fetch.php/modules/datasheet/a6/ai-thinker_a6_a7_a6c_at_v1.02.pdf



Tcp Communication A6 Module

If you want to test the tcp communication with the A6 Module you can follow this tutorial (but use the AT commands for the A6) BUT before, make sure the port is open, go in your router and create a  “NAT”, choose the port you want(something like 747), internal and external(the same), for the device choose the internal IP of your computer.

You can check if the port his open with this website:


(You must creat the server before check the port or it will not work!)

Check his channel because he has a lot of things about Gprs/gsm module, they are for the SIM900 but the A6 is close to this module.

TCP with Gprs Gsm A6 Module

Good news for the A6, there is a simple way for TCP, i wrote in the previous article the long way with AT+CGACT=1,1 because AT+CIICR did not work for me but Simon f found the good order for use it, so i give you his code:


**Power Up**








(we can wait a lot of time, if you see COMMAND NO RESPONSE! do nothing, this mess is send if a command don’t return a message after a while)


+CTZV:16/6/8, 1:33:8:8

















AT+CIPCLOSE               (If you want to close the actual tcp connection)

AT+CIPSHUT                 (If you want to stop the internet connection)

I invite you to go to see his comments for more info and his article!