Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

I would need a little assistance to help a disable friend with a DIY foot mouse

Status
Not open for further replies.
The weight sensors will each measure up to 5kg - so 20kg total. They will bend (very) slightly when a load is detected. They can be set to zero at any point so your friend could place his foot on the board and the sensors could be zeroed. A push on the ball (of the foot) will see the front sensor increase and the back sensor decrease. Same for left/right. The Leonardo can read these sensors and move the mouse at a speed relative to the difference in pressure. It might even be possible to tap the plate to represent a mouse push.

As I had some of these sensors lying around (from an earlier project) I quickly knocked together this.

View attachment 129508
There is (of course) another wooden board which goes on top.
The two circuit boards are (dual) Analogue to Digital converters so the scales can be read.
I have a Leonardo handy so will attempt to write some code when I have time - probably at the weekend.
I'm hoping everything still works as two of the sensors are very corroded.
I'll let you know how it goes.

Mike.
BTW, Sensors and boards work out about US$5 a pair.
Thank Mike for explaining since i was not aware of that type of sensors but this is the kind of tech one have to experiment to see if it could be a good solution because like i mention in another post the cursor need to be immobilize and not be moving while he have his foot on the pedal or else aiming will be very problematic and that's the reason i went for a very basic wasd or keyboard arrows buttons.
And the right foot control the inverted mouse and with the correct dpi value only slight movement of the foot should give him the precision require to play fps or any other type of games. I have already test the inverted mouse and after 2 hours i was able to move the cursor very precisely at 2400 dpi value and this is where the dpi button came in handy since if he want to play as a sniper he can then lower the dpi to something like 800 dpi and have more precision.
 
Seem like the arduino pro micro is enough to make the buttons to emulate a hid keyboard functions :

Back in time i was coding fishbot for one mmorpg game. Thanks to hackshield injecting was difficult for me. So i manage to just read ram and sending code with arduino. Nope UNO was not enough. What i did i connected uno to keyboard and simulate key press. After some time i manage to bypass hackshield =P.
 
The weight sensors seem to work well but I discovered something disappointing. The circuit boards contain a two channel ADC so I was reading two sensors with one module. They can be read at 80 times per second but when you change channels there is a wait time of almost half a second. This means that an ADC module will be required for each sensor. I can (currently) only find three sensors even though I'm sure I bought four. I will persevere to see if I can get forward/backwards to work.

Mike.
Edit, does anyone know a way around this slow response?
 
I was looking for pvc sheet or architectural plastic sheet but hell they cost way too much money so i will go for particle panels instead to build the board.
 
Can someone confirm if this pcb board would be a one on one replacement for arduino pro micro, they say it is but i just want someone who know electronic better than me : https://www.amazon.ca/CANADUINO-Mic...YQH3X25JM4G&psc=1&refRID=B9K2R7MJ6YQH3X25JM4G
I've never heard of a canaduino.
as a starter, you might want a more standard Arduino board - an Arduino Nano
 
He wants (or needs) to emulate a keyboard/mouse so needs one that's capable of being a USB device. Any board that has a ATMEGA32U4 on board should do the job. Assuming the Arduino IDE supports the Canaduino then it should work. However, I too have never heard of Canaduino before. And google doesn't help.

Mike.
 
I've never heard of a canaduino.
as a starter, you might want a more standard Arduino board - an Arduino Nano
Thank gophert i will check this but it will require an additional mini usb cable since the one provide is way too short for my need.
On the other hand the canaduino have one user reporting this here but my knowledge of voltage is not very good :

I have used this Arduino under the specification of the the Pro Micro provided by Sparkfun since they said everything is the same as the OEM one. However, it turns out the voltage regulator is different and rated up to 10V instead of the 12V from the Sparkfun Pro Micro. So I ended up frying up several of the Pro Micros I bought here when I gave an external power supply of 12V. Just something to consider if you're planning to use this in an electronics design.
 
He wants (or needs) to emulate a keyboard/mouse so needs one that's capable of being a USB device. Any board that has a ATMEGA32U4 on board should do the job. Assuming the Arduino IDE supports the Canaduino then it should work. However, I too have never heard of Canaduino before. And google doesn't help.

Mike.

Yes it seem pretty new on the market since search didn't yield much result.
 
I have start building the prototype and now will have to wait for the mouse and electronics to be ship.
 
Would this soldering kit cover my need guy's?

 
The weight sensors seem to work well but I discovered something disappointing. The circuit boards contain a two channel ADC so I was reading two sensors with one module. They can be read at 80 times per second but when you change channels there is a wait time of almost half a second. This means that an ADC module will be required for each sensor. I can (currently) only find three sensors even though I'm sure I bought four. I will persevere to see if I can get forward/backwards to work.

Mike.
Edit, does anyone know a way around this slow response?
Is there any reason you're not just using two weight sensors? i.e. one for X and one for Y. They will give a positive reading if you push, and a negative reading if you pull. Just put a fulcrum in the centre of the foot board.

As an aside, the two channels have different gains; channel A is x128/x64 and channel B is x32, IIRC, and as you said, there's a delay when changing channels, and on the first sample. Have you tried using a MUX to measure different voltages? I'm assuming it wouldn't work, and also assuming that the ADC has an internal strong LPF.
 
Is there any reason you're not just using two weight sensors? i.e. one for X and one for Y. They will give a positive reading if you push, and a negative reading if you pull. Just put a fulcrum in the centre of the foot board.

As an aside, the two channels have different gains; channel A is x128/x64 and channel B is x32, IIRC, and as you said, there's a delay when changing channels, and on the first sample. Have you tried using a MUX to measure different voltages? I'm assuming it wouldn't work, and also assuming that the ADC has an internal strong LPF.
Thank Dougy for the advice but it would be i think a bit too much complicated for me to make and no garantee it will work as intended and the budget is already in the red so i think i will go for the simpler solution with switchs link to keyboard keys.

I need to design a bracket to hold the cherry mx switches and they need to be sturdy enough for foot operations and it need to be the smallest possible to not get in the way of the legs. Also i still have a hard time to find a pro micro clone since most are going to arrive in stock only mid March.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top