Need for Sound

[JavaRN]

Thanks all for your feedback. In the manual for the part of I2C there is:

I2C Bus Communications Along with the 5Volt power supply, the I2C bus just requires the SDA and SCL lines. The I2C interface does not have any pull-up resistors on the board, these should be provided elsewhere, most probably with the bus master. They are required on both the SCL and SDA lines, but only once for the whole bus, not on each module. I suggest a
values of 4k7 for 100KHz and 1k8 if you are going to be working up to 400KHz or higher. If your going for higher speeds than 400KHz then you must separate all bytes transmitted over the I2C bus to the SP03 with a 40uS delay. This is to give the processor time to transfer the incoming data to the buffer. By doing this we have tested the SP03 with SCL up to 1MHz.

Does this mean that I have to add a mod to the connection as I told you I am no good in electronics, or it is just a matter of "plug-code-n-play'?

Charles

[NovaOne]

Yes, sorry.

Its not far from "plug-code-n-play" , you just need two extra resistors.

I connected a 1.8k resistor from SCL (eg port 5) to +5v, and a 1.8k from SDA (eg port 10) to +5v. These resistors can be soldered to the plugs you connect to the MR-C3024 or soldered the SP03 board, (but not on both).

Important. You should get the power from the pin connections along the upper edge of the board only. These are regulated to 5v, where as those down the sides are unregulated and supply power to the servos

The resistor values not not usually critical unless you operate at a high frequency. I'm not sure how fast Robobasic is interpreted, but I am certain its lower than 400,000 instructions/lines per second.

I'll see if I can afford to buy a SP03 in the few weeks, and I will test the code and connections.

Chris

[i-Bot]

Similar to the post earlier, I find the biggest problem on the SP03 to be the low audio volume.

I did the mod described here:
http://www.acroname.com/robotics/info/i ... 03mod.html

I tested with another battery to use 9v on the audio amp, thinking to use a voltage doubler later. Small improvement.

The speaker is rubbish, very low efficiency. I tried a Bose acoustimass cube, and the difference was amazing. Now I have to find something more sensible !

So do be prepared to do something to the audio part too. Maybe speakers in the feet will keep them away from your compass, Ive had little success with piezo etiher.

[NovaOne]

So the main problem for Charles is loss of power due to low efficiency speaker?
Could we get around it with a higher power amp (eg TDA2003) while using the same speaker or has the 4cm speaker got to go?

Chris

[JavaRN]

The SP03 is on its way at last! The Hitec support suggested a 4.7k resistor not the 1.8K. Can NovaOne please post a photo of the final product (the compass connected to the robonova board), so that I can see where to solder the resistors? Thanks a lot for your help and I will keep you informed with my progress. I would like to have the speech module up and running by Monday.
Thanks again and waiting for your photos

[NovaOne]

Your in luck, I've just got mine today. Its cool!

I don't have time to do any I2C testing tonight but I have powered it up and tested it over RS232 with the Devantech configuration/ loader program.

I don't want to scare you off with more electronics, but when I connected it to RN there was a continuous background buzz

This was due noise on the MR-C3024 +5v rail. To smooth it out, I tried various values of capacitor, until I found a 10V 1000uf and fitted it between 0v and +5v. This may just be a problem specific my SP03 or RN?

I don't really need to add any comments about the low volume problem....its a problem I hope we can solve.

After a very quick experiment I found that just enclosing the sides of the speaker/PCB improved the quality noticeably.

On Saturday I will take some photos and maybe draw a diagram, if I get the SP03 working OK on I2C.

Good luck

Chris

PS I would like to enclose the speaker in mumetal to magnetically sheild/hide it, from my compass .... i-Bot I'll keep you posted.

[NovaOne]

As promised here are the photos you requested. I hope you find them helpful.
Red wire +5v from spare terminal above the Rx pin
Black wire 0v from pin closest to edge of PCB on port 15
Green wire SCL connected to output port 16
Yellow wire SDA connected to output port 15


I have fitted my pullup resistors on a separate I2C pcb bus connector in RN chest. I disconnected the compass ribbon so you can "see" the resistors:
Purple +5v
Grey SCL
White SDA
Black 0v

[JavaRN]

Thanks a lot I really appreciate your feedback, but I have some questions to ask you:

1. Isn't the SCL and SDA connection on the top left part of the robot's board? (as labelled in the RN manual).

2. Did I solder the resistors in the right place? I've used a 4.9K resistor, is that ok. What about your resistors are they 1.8K?

2. Can you please circle the ports you used for SCL and SDA in the diagram below (I've used the circled ports):

[NovaOne]

I was unable to connect anything other than EEPROM's to these ports, if anyone else has please step forward?

I use spare output ports for I2C connections as follows:

[JavaRN]

What are the port numbers in Robobasic corresponding to those? How do you get the port numbers? Are they documented somewhere? Thanks again.

Charles

[NovaOne]

Sorry I just realised I didn't answer all your questions:

Yes your resistors are fitted OK

Yes I use 1.8K. Using 4.9k will just mean the lines will not change state as rapidly, but I don't think this will be a problem, robobasic being interpreted and therefore relatively slow

Gook luck Charles

[JavaRN]

Thanks a million!!! One final question From where do you get the port numbers? because the port you circled in the diagram is occupied with the robot's gripper.

Charles

[NovaOne]

I think our posts crossed over.

I may have covered them with my green arrows, they are ports 15 and 16. in group B (look down the red text on your diagram)

They are just spare digital output ports, you can use any that you are not using to drive servos. So long as you alter the addresses for SDA and SCL in your code.

[JavaRN]

Thanks a lot I really DO appreciate your help. I will try everything tonight or tomorrow and let you know. In the meantime I removed the resistors because I thought at first that the problem was because of them and I will fit two other resistors I think I have 1.8K or something in that range I will try them and let you know with my progress.

Thanks again

Charles.

[NovaOne]

I have upload a complete simple test program which should save people cutting and paste headaches:

http://robosavvy.com/Builders/NovaOne/Speechtest.zip

Chris