Show Posts
Pages: 1 2 3 [4] 5 6 ... 13
46  Using Arduino / Microcontrollers / Faster i2c speed? on: August 31, 2013, 07:47:35 am
I have an 8Mhz 328P with an animation on a small i2c display working pretty slow. I thought I could speed it up slightly by adding the line TWBR = 12, 2 or 24 to the void setup(void) under wire.begin(); but the animation speed is always exactly the same. Overclocking for test purposes is fine.
47  Using Arduino / Storage / Re: Anybody need memory cards? on: August 28, 2013, 11:30:15 am
I could grab 10pcs or so but 600 pcs is pretty crazy.
48  Development / Other Hardware Development / Re: Leonardo clone circuit check on: August 23, 2013, 05:22:33 am
I have pin33 connected directly to ground but your goes through a 10k resistor. Not sure if it matters so you should check the data sheet. I think it has something to do with the bootloader on power up. Other then the VUSB to ground mentioned way back your schematic looks good. Sorry for leading your post in a different direction but it's started some interesting discussions.
49  Development / Other Hardware Development / Re: Leonardo clone circuit check on: August 22, 2013, 08:55:27 am
Thanks for the feedback CrossRoads. I've updated the schematic with the 22R D+ & D- resistor values as well as changing the 10K i2c pullup values to 4.7K.
I've read that others have overclocked the 32u4 @ 16Mhz with good results. The only reason i'm doing this is because I use the default Leonardo bootloader and program blank chips using the USBtinyISP. If I ever figure out how to tweak the frequency then I'll give it a try along with a modified PID/VID.

About the SPI SS line. Right now SPI only talks to the SD card. Should the SD_CARD_CS line on the SD card holder be connected to the 32u4 pin 8 PB0(SS/PCINT0) ? Right now I can read and write to the SD card so I must have the SS line configured as an output.

S2 is just a simple pushbutton so I have the 10K pull down as used in all the simple button examples.

50  Development / Other Hardware Development / Re: Leonardo clone circuit check on: August 22, 2013, 07:24:40 am
Looks good to me.
51  Development / Other Hardware Development / Re: Leonardo clone circuit check on: August 22, 2013, 06:41:14 am
This is my 32u4 working at 3.6v connected to a 5v usb connector. it works fine so far but feel free to make any comments CrossRoads on how it can be improved.
52  Development / Other Hardware Development / Re: Leonardo clone circuit check on: August 21, 2013, 02:23:46 pm
I've done two working designs using the 32u4. One is like yours with Vcc @5v and other one split up. The USB parts @5v and Vcc @ 3.3v. Just send let me know if you're interested in the other schematic.
53  Development / Other Hardware Development / Re: Leonardo clone circuit check on: August 21, 2013, 01:47:16 pm
-I've seen 33 ohm resistors between the the USB D+ & D- going to the micro on other designs.
-Pin7 (VBUS) goes to GND which is bad.
-with my design I've seen a 0.1uf or 1uF cap from Reset (pin 13) to GND is sometimes needed.

54  Using Arduino / Storage / SD card log data to OLED or LCD screen on: August 16, 2013, 01:42:32 pm
I was wondering if anyone has a code snippet of displaying a csv log data on the SD card to the display? Right now I can use the example from the SD library:Serial.println(dataString); to view the data on the computer screen but I need some way of breaking up the dataString for the display, then moving down a line and displaying the next log. Right now I can log data, stop logging, verify the log exists by viewing it on a pc, then clearing the log file. I wont post my code since I just need a basic idea of what to do.
55  Using Arduino / Storage / Re: I need help!!! on: August 08, 2013, 11:11:50 am
I'm just getting started with SD cards myself and found this tutorial helpful:

I would start by writing one number or letter to the card and slowly building from there and adding your code a bit at a time.

56  Using Arduino / Storage / Re: Smaller SD library on: July 29, 2013, 09:19:00 am

Thank you.
57  Using Arduino / Storage / Smaller SD library on: July 29, 2013, 06:59:49 am
I have modified an existing project by adding an SD card but the standard SD library is so large that i'm out of code space. Can someone recommend a smaller SD library that I can use for cards under 500 megs or smaller in size? I did some digging this weekend and found one that some created 3-4 years ago but have not given it a try yet.
58  Using Arduino / Microcontrollers / Burning Leonardo bootloader difficulties on: July 24, 2013, 06:51:27 am
I've had difficulty burning the leonardo bootloader into the 32u4 since day one for some reason. The designs are all different and eventually works after a few repeated tries. The hardware used is:
-windows 7
-adafruits thru hole USBtinyISP
-sparkfuns SMT version of the USBtinyISP
-32u4 @ 3.3V and also 5.0V
-16Mhz crystal
-Arduino IDE where I select Leonardo and burn bootloader

Occasionally the bootloader will successfully burn on the first try but usually it requires another attempt, power cycle, trying on another PC, power cycle and then it works.

I'm wondering if I might have better luck with the AVR ISP MkII abd the Arduino IDE? Possibly more complicated route of installing the Atmel software, setting the fuses manually and then burning the bootloader hex file. So far i've been cheating by just using the IDE.
59  Using Arduino / Microcontrollers / uploading sketch using USBtinyISP and no boot loader on: July 19, 2013, 07:59:18 pm
I've only installed bootloaders in avrs and then uploaded the sketch over USB. For my next project I would like to program the sketch into the avr using the USBtinyISP. The project will only be powered by USB and the sketch has been tested and works fine. Is this possible and how would I do this using only the IDE?
60  Using Arduino / Displays / Re: Crius OLED display on: July 19, 2013, 07:50:16 pm
No worries. If you're having as many difficulties as I did and still interested, the board I can send will come fully populated with all the parts and glass soldered. All you need are two 10K pullups and an arduino.
Pages: 1 2 3 [4] 5 6 ... 13