I do need a cheap 12V dc async ascii printer (ttl or rs232/485/422).

Thread Starter

Picbuster

Joined Dec 2, 2013
1,008
I build a chronometer based on a pic18f8722 to be used in sailing contests.
A build-in GPS will guide to correct position.
The system does the start procedure and is able to keep track on several classes starting in sequential order. The output should be on paper and looks like

Start Grp1: 10:00:00
Start GRP2: 11:00:00

Finish1: 7410 sec
Finish2: 8088 Sec

I do need a cheap 12V dc async ascii printer (ttl or rs232/485/422).
Anybody know what brand to buy?

DSC_0090_1024x680.jpg
 

ScottWang

Joined Aug 23, 2012
6,912
The files size that you attached were too big, I was compressed it to the normal size, it was from about 2.3MB compressed to about 100KB, next time before you upload the files, please compress the photos to 800x600 or 640x480, if necessary then you can compress to 1024x768, almost the photos using 800x600 image is enough.

Too much file size will affecting the connecting speed of members to get into the forums, thanks for your understanding and cooperation.
 

spinnaker

Joined Oct 29, 2009
7,835
They are cool. But did you think about logging to an SD chip? It would be more "bullet proof" out on the water. Or do you need the printed output immediately?

Sounds like a great project. You are using this on your boat correct? As opposed to the committee boat?
 

Thread Starter

Picbuster

Joined Dec 2, 2013
1,008
Yep,
Part of commitee boat.
It’s on flash also.
The paperwork is to ensure that no mishap can destroy results.
Next enhancement will be the photo and storage at SD. (no way to get this in time on paper).
I am thinking of sending it to a Samsung Phone using BT.
But that implies a new PCB layout.
All parts in a IP68 enclosure.
I make my poor PIC18F8722 run like hell. (paid 8,75$ for it so it should run for that money)
Simple projects are fun and that is what is should be.
 

spinnaker

Joined Oct 29, 2009
7,835
Why do you need to know the position of the committee boat? Or is the GPS just to get the time?

This is pretty nice for SD memory.

http://elm-chan.org/fsw/ff/00index_e.html

It took a little bit of modification to get it to work. It was also a challenge to figure out how to allocate enough memory for the FAT. Not sure how hard that is under XC8.
 

Thread Starter

Picbuster

Joined Dec 2, 2013
1,008
Both the commitee goes out to sea let say 20Nm from shore ( it has its own nav stuf but I want this information on the results)
GPS Time not accurate due to transmission will take one sec however; as a clock sync trigger it is ok hence match is a relative time but takes absolute seconds to hit the finish.
xc8 will work but the chip mem( blocksize) is a problem. I made it to works with 18f8722. takes about 70KB.
Use ftdi master I am implementing it now.
 

mcgyvr

Joined Oct 15, 2009
5,394
Great info have one works great.
Build a 3 Amp step down 24=>8.5V to feed printer and hardware.
Thank you excellent advice!
No problem.. I've used 3 so far and they work great.
Just hooked one up today actually to a test station at work with an Arduino, 4.3" TFT, 2D Barcode scanner and this TTL printer to capture product test data.

Note: you can find the paper on Staples or other sites for cheaper than they have it there at adafruit.. I got a couple 5 packs at Staples.
 
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