Service Forum

[Chapie]

Hi,

My simple circuit was driving me crazy with the same old "eeprom not found" errors on 2 pc's, so i want to try the driver circuit (hope that this one works lol).

I have a couple of questions:

1. Are these parts good for a driver circuit?

2. I dont have any micro grabbers, are those needed or can i just use a needle (eeprom) and a normal (utp) cable for the breadboard (plug it in a hole).

3. I heard the cables inside an utp cable are good enough for a breadboard/eeprom. Is that right?


MAX232 RS 232 transceiver
1N 4148 diode. Max 75 volt 150 ma
Ceramic condensator 100 nf 50 volt. Raster RM 5,8
4.7k ohm resistors, 0,25 watt / 5%
Sub-D connector female 9pin
Standard Bread board












Thanks

[victor]

For a simple MAX232 without any termination you must have 1uF electrolytic capacitors. Those are polarized (have + and -)

I suggest you to take a look at Ray Kawakami's pictorial (he posted a link in the "Practice" thread) about how to mount the pieces onto a breadboard:

http://webzoom.freewebs.com/rkawakami/ibm_600x/max232_if/simple_layout.jpg
http://webzoom.freewebs.com/rkawakami/ibm_600x/max232_if/power_strips.jpg
_________________
Victor Voinea
ALLservice HQ, Romania.

[dramacydril]

[victor]

They are OK, but could be a little bigger if you design a smaller setup.

Nah, nothing to explode there...
_________________
Victor Voinea
ALLservice HQ, Romania.

[dramacydril]

I bought all the stuff and put the driven circuit together without the batteries. I also couldnt find any solid core cables so i used the cables inside a standard network cable (also non solid core) I have a x201 laptop.

The following setup doesnt work, i dont get any voltages, nothing, nada. I think im doing something wrong.

I got the setup from the following image;


As you can see the TO SDA and TO SCL are connected by 2 grabbers. I didnt have those so i tied the SDA / SCL cable to the little orange cables on the breadboard. That didnt work, so i tried to move the sda/scl cables one hole down, look at the 2 black lower dots (doesnt work also). The middle left MKT capicitator is touching a leg of the chip, i dont know if that is a problem, i can solder some longer legs to it.



[img]

What am i doing wrong?

Thank you

[victor]

The jumper at A2 in the left upper corner is wrong resulting in a short circuit
_________________
Victor Voinea
ALLservice HQ, Romania.

[dramacydril]

Cable fixed.

I connected the circuit to the com port and tested with itester but that doesnt go wel. I dont get the pairs 11 - 00 -11 -00

I checked the voltage on the scl sda gnd cables but it is very low. Like 0.2v.
I think its important to mention that i used the inside cables of a standard utp cable. I read today that these can only give you like 2.5v max.

Previously i had made the simple circuit which gave me 5.7 volts, so i think power is not the problem?

Should i buy the battery holder with batteries or double check my interface?

[victor]

Buddy, I said that you must fix the crossover lines on the left. Did you do that?
There is a short between + and - lines. Check again.
_________________
Victor Voinea
ALLservice HQ, Romania.

[dramacydril]

[dramacydril]

I read on the forum that you need the batteries for soldered eeproms (in the pdf file it says unsoldered???). Maybe thats the problem? Because i tried like a 10000000 times in different ways and i dont get nothing, no volt nada. It must be the batteries

Again: i dont use a unsoldered eeprom, i use the laptop power.

I bought these 2 battery holders. They didnt have the 3 battery version so i bought a single one and a double one to get the 5.1v.



and



The guy in the store said i have to connect the cables: RED (+) to BLACK (-) and BLACK (-) to RED (+) cables together so i get the 5.1V, but if i do that, what is the negative and what is the positive, cuz they are merged together now?

I dont want the batterys to explode in my face lol. Cuz they get hot right now.

Sorry, im not a electronics pro

[bob]

dramacydril, You won't gonna make it this way. Not a chance!

Why don't you save a headache and buy a professionally made driven interface? We used 3.3V TTL Sipex RS232 for the best compatibility for in-circuit programming.
Here is the order form.

Cheers

[dramacydril]

[victor]

As far as I see you and other guy Chapie are the same person. So Chapie has been disabled.

Give me one reason to not delete this account too, cause what I see here is too funny..
_________________
Victor Voinea
ALLservice HQ, Romania.

[dramacydril]

[victor]

After I've read your posts, I admit that I somehow understood.
_________________
Victor Voinea
ALLservice HQ, Romania.