DIY Mares InfraRed Cable for AirLab/M1/Dacor Darwin -- Works!

[Don954]

MrSpock, i looked at the sketched schematic and i have some questions for you since you have already ordered parts you must know the answer..

On Mr Cardew's schematic what kind of diode did you order in place of the ones just below the 4040(no values)?

What transmitter diode did you order?

What are the components up in the top left between pwr/gnd. I see a cap, diode, and something else and theres no values for them?

So thank you MrSpock for your reply to the above. For others wondering some of the same things as myself i will tell what i have found. The diodes below the 4040 are there to eliminate transients and control voltages. Also the neat little thingy up in the top left of Mr Cardew's schematic is a polarized cap which is a new way of depicting it to me but then i'm not an electrical engineer only a mechy as my elec friends say. Not sure yet but it might also be specifying a Tantalum Cap... i'm going to have to check on that though.

I'll be running some tests on first prototype in the next couple days. I'll report back.

Don

 

[MrSpock]

You are welcome, Don. The "little thingy" is an electrolytic cap. It's just US vs. European drawing standards. It's there to filter power "noise".

I'm gonna use Eagle (free schematic/layout editor: CadSoft Online: Freeware) for prototyping and will re-create the schematics there. If the whole thing works, I'll post thorough instructions, notes, pictures, and perhaps, if size permits, upload the Eagle project. If it doesn't work, well... I'll post here anyway.

I haven't got a chance to dive with my new M2 yet, but so far I like it. Friend of mine promised to bring me old 9-pin serial mouse tomorrow - I'll use it as an enclosure.

 

[Don954]

You truely are going down the same road.. I was planning on using Altium 6 at school do a layout and possibly have a PCB made but i think i'm gonna use proto board instead.

And i just found that it is not nessesarily Tantalum...

I also have just received my M2 and have not dove with it either but i like it so far. My co worker is going to give me a 9pin mouse next week

 

[Don954]

Breadboarded tonight... no luck, keeps timing out. Checked all connections good, checked all component values good, checked datasheet info good, checked com port settings good...

 

[MrSpock]

If you don't have an oscilloscope try temporarily replacing IR emitter with LED. See if it blinks and reacts on Tx-Rx commands. Check voltage per instructions on MARES IRIS Interface schematic circuit and make sure the oscillator works.

 

[MrSpock]

Quote from www.EKTM.de - Re:Working IRIS interface at last! - EKTM-Forum :

This is what I saw when I tested the interface:
-Communication is always at 9600, so an error correction protocol must be used
-PC starts sending a short sequence of bytes (some milliseconds). On the IR LED you should see the carrier at 56kHz, modulated at 9600
-At the same time the TSOP may catch the reflection of the IR LED, so you should see the demodulated signal
-After some ms, dive computer answers with another short sequence
-This handshaking is repeated several times (during this period progress bar in IRIS remain empty)
-If interface is properly aligned (just in front of DC at about 2cm), progress bar starts filling. Communication is on polling: PC sends a short sequence of bytes, then DC answers with a longer one (about 200ms), then again PC, then DC. This exchange of bytes is repeated several times: the more aligned and closer is the interface, the longer is this communication.
-When communication stops (I suppose because an error occured and was detected), there is a long pause and then communication starts again.

 

[Don954]

So, i re boarded the schematic a couple times and i scoped it with an old asz picoscope. scope didn't help much but i did get confirmation that the TX side of things is working. At least its sending predictable pulses to the IRLED every second or so. I couldn't get any useful information out of the receiver side though. BUT i DID notice the loading bar on IRIS software start to fill a few times but then i got a Timeout error again.

I beleive i am getting closer. I want to assume the reason it never stayed in contact was due to noise from shoty breadboard skills, or imperfect placement of the DC. So i may just try soldering it into some proto board and try that.

I have been translating the conversations at EKTM to english with online translator and i came accross one guy that mentions changing a 1k resistor to a 100ohm and some other changes too but its unclear to me yet...

Where are you at with your circuit now MrSpock?

 

[MrSpock]

You are way ahead of me, Don. I'm planning to breadboard the circuit today or tomorrow. I'll post the results.

 

[MrSpock]

Found a COM port sniffer program. It helps in debugging.
Monitor Serial Port activity from Application, Serial Data Monitoring, Serial Port Sniffer :: Features

 

[MrSpock]

Don, here is my status report: Transmitting woks. M2 replies, but the reply is getting scrambled. Without oscilloscope I can't even tell where and why. I ordered TSOP4156 IR module, will try as soon as it arrives. COM sniffer helped a lot - I could see what's getting in and out.