TSL1401 With and Propeller, not a lot of info
rwgast_logicdesign
Posts: 1,464
So the other day I ordered an OV7670, off ebay. When I ordered the camera I new it would not be easy to get working, and there is a good possibility I may never get it working well with a propeller. I did however search around and I found a project on youtube where the camera was used to do color tracking with an Ardunio, so that shows me it is quite possible to get the thing up and running, probably just not so easy, if it is anything like the camera on the CMU, and laser range finder, for things I have read by both Joe Grand and Kye, Interfacing to OV cameras is not simple, and they don't give a lot of documentation. Anyways It was 7 bucks so if it never works O well....
Ive been looking in to the TSL1401 for the past few days and it seems fairly capable of doing what id like. Basically Im just looking to track beacons and lasers, so with a little modulation I think things would work fairly well. Although I am interested in doing some other experiments. Ive read a lot of stuff on the forums about this sensor, the problem is, its mostly based around the Bs2 motherboard with the AVR chips.
I know there is a propeller object out there for this CAM, but by reading the description it looks like it can only do digital threshold values? Im wondering if one were to use an ADC like the mcp3208 would it be possible to do full scans of images like the example with the dollar bill alot faster than the bs2 mobo could do it, I think I read that scan took 2 minutes because of the slow serial connection? What would be the fastest one could scan a full image. More specifically im asking this for finding a beacon, If the thing is just randomly panning around until it sees a modulating light, it seems like you would have to be analyzing the data failry quickly.
Also I noticed you can get the Attiny hex file that has the firmware for the bs2 mobo, any chance of getting the source to that file? How complicated would it be to get the attiny13 talking to a prop instead. While im sure using a prop and ADC cuts out the need for the AVR chip, all the examples for this sensor and software for the PC seem to rely on the chip.
Also would there be any advantage to using two of these sensors, I know there is a thread about a stereo TSL1401 set up, but it didnt really seems to contain to much useful information.
Ive been looking in to the TSL1401 for the past few days and it seems fairly capable of doing what id like. Basically Im just looking to track beacons and lasers, so with a little modulation I think things would work fairly well. Although I am interested in doing some other experiments. Ive read a lot of stuff on the forums about this sensor, the problem is, its mostly based around the Bs2 motherboard with the AVR chips.
I know there is a propeller object out there for this CAM, but by reading the description it looks like it can only do digital threshold values? Im wondering if one were to use an ADC like the mcp3208 would it be possible to do full scans of images like the example with the dollar bill alot faster than the bs2 mobo could do it, I think I read that scan took 2 minutes because of the slow serial connection? What would be the fastest one could scan a full image. More specifically im asking this for finding a beacon, If the thing is just randomly panning around until it sees a modulating light, it seems like you would have to be analyzing the data failry quickly.
Also I noticed you can get the Attiny hex file that has the firmware for the bs2 mobo, any chance of getting the source to that file? How complicated would it be to get the attiny13 talking to a prop instead. While im sure using a prop and ADC cuts out the need for the AVR chip, all the examples for this sensor and software for the PC seem to rely on the chip.
Also would there be any advantage to using two of these sensors, I know there is a thread about a stereo TSL1401 set up, but it didnt really seems to contain to much useful information.
Comments
The documentation shows a test program that uses any BS2. It uses a threshold because the BS2 doesn't have an ADC. You could certainly add one, but that would slow down the scan because of the conversion time and the time to get the 8-bit value in. The Prop, of course, can do the ADC by itself as well as using a threshold like the BS2 version.
Regarding the "how fast could it be" question ... You could probably figure that out for yourself from the sample program and the datasheet.
http://forums.parallax.com/showthread.php/117941-RedEye-A-linescan-imager-based-BOE-Bot-line-follower/page2
What I did was port Phil's line following example to the Propeller chip using thresholding. I've also used an ADC in Spin for about 3 frames per second, and Phil's Sigma delta code for substantially more than that.
Lawson