2017-01-06, 06:02
(Modification du message : 2017-01-06, 06:12 par Oran.
Raison de la modification: Resize photos and tidy layout of text.
)
This is the data logging setup I've been using. The wires have broken again at the connection to the header pins and I've got more than enough data for the moment so its time to rethink it. I've just ordered a data logging shield for an Arduino Nano to give it a go. I'd like to incorporate it into my new two Arduino design so I always have the option to log data if I want to.
![[Image: kwQMYJ.jpg]](http://imageshack.com/a/img923/6994/kwQMYJ.jpg)
![[Image: wOOIVe.jpg]](http://imageshack.com/a/img923/8941/wOOIVe.jpg)
Next stage of the project is to work on the user interface. I have a few ideas and I'm not sure at the moment if any of them will be the perfect solution. Part of me wants it to be a bicycle that you just switch on and ride with very few extras to get damaged by weather. Maybe have a switch to change between two cadences and modes changeable by mobile app and Bluetooth. This is what I've been using for the past couple of weeks and it works quite nicely. The potentiometer isn't that great when it comes finding the right cadence, it needs some form of indexing. A downtube shifter attached by cable to a linear potentiometer which can be in a waterproof enclosure has potential. There's also a possibility of adding a potentiometer to the original shifter which I think could work nicely. Would make it very easy to use like a normal bike only better. Both would need some sort of spring arrangement to tension the shifter in the same way as the derailleur would.
Next option is to go all fancy and add a display. There are some impressive looking touch screens available which have a user interface that is fully customizable and dealt with by the screens own possessor. This make the Arduino programming very simple in comparison. This opens up all sorts of options to input different modes change cadence and display information such as speed, cadence, battery voltage etc. The disadvantage is increased power consumption, waterproofing and being able to see it in full sun and press the right bit when the bike is moving.
So a couple of decisions to be made, Bluetooth or LCD touch screen and potentiometer in a shifter or simple switch.
Also I would be interested to see how accurate I can get it to maintain a cadence. In its current state its perfectly fine and eventually I want to connect the servo to the hub via 2 gears which will help. There are times due to cable slack and the plastic shift interface that cadence can vary by around 10rpm as the shift direction changes. To fix this would require sending the cadence value from the data logging Arduino 2 to the main control Arduino 1. I'd add the cadence value into the main equation to make small alterations, speed would still mostly determine the servo position.
Would be interesting to see how well shifting by cadence sensor alone would work.
I quite like the idea of two Arduino's working together for reliability, see drawing. Both able to take control of the servo and send information between each other and know what to do if a response wasn't received. One would measure speed the other cadence. Under normal conditions the speed or main control Arduino 1 would do the shifting taking cadence values from Arduino 2 if required. If Arduino 1 failed Arduino 2 would take control of the servo and use Timer 2 for PWM instead of cadence measurements.
![[Image: hHMkFg.jpg]](http://imageshack.com/a/img924/6671/hHMkFg.jpg)
How everything is going to connect together and how far I want to take this I'm not sure about at the moment. Next stage is to get Arduino 2 data logging and receiving mode settings from Bluetooth. Then get Arduino 1 to receive mode and cadence values from Arduino 2 and make use of them.
Sent from my BV5000 using Tapatalk
Next stage of the project is to work on the user interface. I have a few ideas and I'm not sure at the moment if any of them will be the perfect solution. Part of me wants it to be a bicycle that you just switch on and ride with very few extras to get damaged by weather. Maybe have a switch to change between two cadences and modes changeable by mobile app and Bluetooth. This is what I've been using for the past couple of weeks and it works quite nicely. The potentiometer isn't that great when it comes finding the right cadence, it needs some form of indexing. A downtube shifter attached by cable to a linear potentiometer which can be in a waterproof enclosure has potential. There's also a possibility of adding a potentiometer to the original shifter which I think could work nicely. Would make it very easy to use like a normal bike only better. Both would need some sort of spring arrangement to tension the shifter in the same way as the derailleur would.
Next option is to go all fancy and add a display. There are some impressive looking touch screens available which have a user interface that is fully customizable and dealt with by the screens own possessor. This make the Arduino programming very simple in comparison. This opens up all sorts of options to input different modes change cadence and display information such as speed, cadence, battery voltage etc. The disadvantage is increased power consumption, waterproofing and being able to see it in full sun and press the right bit when the bike is moving.
So a couple of decisions to be made, Bluetooth or LCD touch screen and potentiometer in a shifter or simple switch.
Also I would be interested to see how accurate I can get it to maintain a cadence. In its current state its perfectly fine and eventually I want to connect the servo to the hub via 2 gears which will help. There are times due to cable slack and the plastic shift interface that cadence can vary by around 10rpm as the shift direction changes. To fix this would require sending the cadence value from the data logging Arduino 2 to the main control Arduino 1. I'd add the cadence value into the main equation to make small alterations, speed would still mostly determine the servo position.
Would be interesting to see how well shifting by cadence sensor alone would work.
I quite like the idea of two Arduino's working together for reliability, see drawing. Both able to take control of the servo and send information between each other and know what to do if a response wasn't received. One would measure speed the other cadence. Under normal conditions the speed or main control Arduino 1 would do the shifting taking cadence values from Arduino 2 if required. If Arduino 1 failed Arduino 2 would take control of the servo and use Timer 2 for PWM instead of cadence measurements.
How everything is going to connect together and how far I want to take this I'm not sure about at the moment. Next stage is to get Arduino 2 data logging and receiving mode settings from Bluetooth. Then get Arduino 1 to receive mode and cadence values from Arduino 2 and make use of them.
Sent from my BV5000 using Tapatalk
- Oran