Discussion in "New Ideas regarding projects" started by    jona    Oct 19, 2014.
Sun Oct 19 2014, 07:33 am
#1
Has anyone used this device? I was able to get the datasheet from the seller, but it says "The information contained herein is the exclusive property of TONTEK and shall not be distributed_ reproduced or disclosed in whole or in part without prior written permission of TONTEK", though I'll share it if anyone wants to see.
Apparently one needs to solder header pins to the board in order to configure the board. What's not explained is what the sixteen bits of data mean, 16 switch codes could be contained in a single nibble. There are SCL and SDO pins, strikingly similar to I2C, but when I probe the device for an address (I wrote a small program that searches for all the devices on the I2C bus, a good first step when facing a new device) nothing comes up. A larger version of TTP229, without the B suffix, does support I2C, and that's what I was expecting when I bought the board. It's also not explained if I have to continuously probe the keypad, which would make the board somewhat useless.

I can't figure out how to attach a photo, the device can be seen at ebay # 321526094805


[ Edited Sun Oct 19 2014, 07:35 am ]
Mon Oct 20 2014, 04:47 pm
#2
You can use the attach file button to attach the image. However I have not worked on this device. But if the information is so sensitive to be disclosed then it will be difficult to help and provide input. Can you post direct link to eBay? Coz eBay stores varies from country to country.
Tue Oct 21 2014, 02:14 pm
#3
This is the part I bought
http://www.ebay.com/itm/371062592514?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D371062592514%26_rdc%3D1
Tue Oct 21 2014, 10:51 pm
#4
I found this slightly different data sheet on a public site,
so don't think there are any issues with sharing it.
I'm having problems attaching files,but this is the link.

https://www.openimpulse.com/blog/wp-content/uploads/wpsc/downloadables/TTP229-Capacitive-Touch-Sensor-Module-16-channels-Datasheet.pdf



From a quick skim it seems the module is read only.
That is ,you must keep asking for any keypresses and can't change its operation.
The interface is I2C, but one of the other pins *may* act as an interrupt when a key is pressed.

TTP229-LSF Slave Device Identifier and Address => [1010 111R]


[ Edited Tue Oct 21 2014, 10:56 pm ]
Wed Oct 22 2014, 03:59 am
#5


I found this slightly different data sheet on a public site,

ExperimenterUK


I hate to be too contrarian, but the pinouts for the -L and -B devices are very much different. E.g., Vss is pin 28 on the -L device and pin 27 on the -B device, so the power pins are even different. They are entirely different creatures. Fewer than half the pins are the same. My -B device has no SDA and doesn't respond to my I2C scan program.
Wed Oct 22 2014, 08:52 am
#6
Okay, it seems to be a simple serial connection.
The interface can be active high or low,
Check the level on SDO, if it's high I'd assume the connection
is set to active low.

For active low operation hold SCL high most of the time.
To read a key, set SCL low, then high, repeat 16 times.
On every rising edge note the level on SDO.
I'm guessing the key number is given by a single bit
position being low

Reverse the logic for active high.



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