Let’s break this down.
I started this conversation assuming you had checked the data sheet and that you aware of the number of ADC pins on the 08m. We then spent an hour discussing options via the shoutbox. During that discussing you said you wanted to control the robot via the computer and would need a rs232/ttl converter. Then you said you were lazy and didn’t like to send data back-and-forth to the computer. We eventually got to the fact that you wanted to make a simple hand-held remote and you told me that you didn’t have the adc pins you needed. Again, I assumed this whole time that you had done some research before asking your question so I did not question the fact that you were short one ADC pin.
After about an hour of going back and forth, I finally went and RTFM and quickly found that yes, you have all the pins you need. At that moment, I found that I had wasted 1 hour of my life discussing a problem that did not exist --An hour I would not have wasted if you had done a tiny bit of research before asking your question. You have been around long enough to know better.
After this, the conversation ended with: “pips17: i’ll just see if anyone with some knowledge answers the post”. Really? Really? I gotta tell you, you can be sure I won’t make the mistake of trying to help you again.
Let’s go over the facts:
You didn’t look up a God Damn thing before asking your question. You (based on the “someone with knowledge” comment) were pissed at me because I didn’t look up the pin-out and assumed you did.
You thought you didn’t have enough pins and are stuck on using a RC decay timer on a 555 circuit to add a ADC channel. --This makes no sense at all. A 08m costs $4, a 555 is around $2 plus all the parts you will have to add to build your 555 circuit. Now we are in the $7 or $8 range with is what you would spend on a 28x1 or 28x2. You are spending the same amount of money here for either option so why would you want to go through all the bull ■■■■ of building a circuit, testing it, stuffing this second chip into your transmitter case, etc. etc. etc. Instead, AS I SUGGESTED IN THE FIRST PLACE, just upgrade to a bigger chip FOR THE SAME AMOUNT OF MONEY and just use the ADC as it was intended. Not to mention, if you are an arduino guy and are switching to picaxe for this project, you will be testing a new circuit (the 555 thing) at the same time you will be learning code --why would you double up on things that can go wrong? Simple is better.
Now, if you are curious about measuring analog values using the RC method, fine. I think it is cool too and understand that you would want to experiment with it. But in terms of the question you have asked, this is irelavent. It is not needed, complicated and will slow you down in terms of getting this particular project done. But then again, you may want to find someone with “knowledge” to confirm this.
The bottom line is, you knew what answer you wanted before you asked for advice. During our conversation, I was not giving advice, I was wasting an hour of my life while you tried to convince me that the answer you had already decided on was the right one. So do whatever the hell you want. Make you RC/555 circuit and play to your heart’s content. Wire your TX unit to a 08m, an Arduino or your asshole for all I care, when you discover that you have no way of timing with the 08m using the RC method of reading analog values, don’t call me. When you discover that 256 bytes of program space doesn’t go very far at all and your program won’t fit --don’t call me. When you find you need 9600 baud and you have to over-clock to get it and all your pauses are weird, don’t call me. When you find that you wasted $4 on a 08m and should have spent $8 on a chip that is many, many times the size, twice as fast with a ■■■■■■■■ more program space --don’t call me. When you fill-up every pin of the 08m, want to upgrade in the future, and only then find you should have bought a bigger chip in the first place, don’t call me. Call someone who has actually worked with all these chips, read the data sheets and has “some knowledge” on the subject. You have lost my help.