08-25-2020, 01:31 PM
Hi Jan,
very interesting project I found today in the German "Heise-online" article and congratulations for this great idea and the complete instructionss and more...
Since I´m also doing some Arduino programming and 3D printing I have read everything to understand in detail what is done here. :-)
Currently I do not have abike but waiting for my dream bike is back in production. Seems that a lot of parts from China are missing and production in Germany is on hold.
However I developed an Arduino Mini based anti-thief alarm circuit with 105dB sirene based on a acceleration sensor.
And here comes my idea for an improvement of your electronic design. I used a LiOn single cell 18650 (3450mA), a DC StepUp converter (3A) and a LiOn charge / protect module.
The cell has a an output of 3.7 - 4.2V nominale and can be discharged until 2.9 safely. The output voltage can be adjusted via the DC Buck-converter to 6V for the Arduino and servo. So there is no need for 2 batteries. Additionlly I would not use NiMH cells due there is still a little memory effect but also I would say that your charging concept with 2 cells packets in row with different voltages and different discharge current is not very healthy for them. All cells placed in row should have the same dischrage level before charging them.
Here I have attached some links to cells and the modules. maybe you think about this for a future design.
https://www.conrad.de/de/p/samsung-inr18...99572.html
https://www.amazon.de/Lademodul-Schutz-A...B07FB6PLKM
https://www.amazon.de/LAOMAO-Step-up-Con...MDQQ6DHNE8
https://www.conrad.de/de/p/panasonic-ncr...36402.html
very interesting project I found today in the German "Heise-online" article and congratulations for this great idea and the complete instructionss and more...
Since I´m also doing some Arduino programming and 3D printing I have read everything to understand in detail what is done here. :-)
Currently I do not have abike but waiting for my dream bike is back in production. Seems that a lot of parts from China are missing and production in Germany is on hold.
However I developed an Arduino Mini based anti-thief alarm circuit with 105dB sirene based on a acceleration sensor.
And here comes my idea for an improvement of your electronic design. I used a LiOn single cell 18650 (3450mA), a DC StepUp converter (3A) and a LiOn charge / protect module.
The cell has a an output of 3.7 - 4.2V nominale and can be discharged until 2.9 safely. The output voltage can be adjusted via the DC Buck-converter to 6V for the Arduino and servo. So there is no need for 2 batteries. Additionlly I would not use NiMH cells due there is still a little memory effect but also I would say that your charging concept with 2 cells packets in row with different voltages and different discharge current is not very healthy for them. All cells placed in row should have the same dischrage level before charging them.
Here I have attached some links to cells and the modules. maybe you think about this for a future design.
https://www.conrad.de/de/p/samsung-inr18...99572.html
https://www.amazon.de/Lademodul-Schutz-A...B07FB6PLKM
https://www.amazon.de/LAOMAO-Step-up-Con...MDQQ6DHNE8
https://www.conrad.de/de/p/panasonic-ncr...36402.html