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Everything posted by ailee

  1. Hi I'm need to write 1 byte of data to eeprom memory and struggling to find a working example, I read the data sheet but it leave more questions then it answers. Googled without too much luck. So may I tell you what I've think and maybe you would be kind enough to put me straight. I code below is the extract of my full code but its not working. Questions, 1) the Address, does this start a 0 or should it be a physical address? can't seem to find anything explaining this and whats is the physical address 2) I've see interrupts should be disabled, but others are sa
  2. I have a cheap Altera Cyclone II EP2C5T144C8 Dev Board and a few (4) of the IO/LVDS pins are shorted to VCC or GND as shown in the schematic segment below. The pins are also brought out to headers on the board. The only things I can think of for why they are there are: They are meant to be left non-populated (but were accidentally populated) for the user to add pull-up/pull-down resistors They are somehow helping power the FPGA Is there any reason a direct short to VCC/GND would be desirable for an IO pin on a Dev Board? Can I remove these resistors without negatively impa
  3. MT9M001 is a CMOS image sensor. As its output it provides FRAME_VALID, LINE_VALID and DATA. The output signals are synchronized (edge-aligned) by PIXCLK, which is generated by the sensor. The datasheet is for example at I read the senosr output using FPGA, it somehow works, but I have a hard time understanding timing of LINE_VALID. Since this is the most critical signal for the image shape, I cannot ignore these problems anymore. The datasheet claims that the maximum frequency of the camera is 48MHz. This is the frequency I use
  4. I would like to develop an application with Nordic's nRF8001 DevKit. The master emulator of this kit is an USB Dongle and it is originally meant for PC connection. My final goal for the project is to run it on an FPGA (possibly through Embedded Linux). Regarding this goal, I have some questions. 1) Is the master emulator (USB Dongle) compatible with Linux? Are there any open-source drivers or from Nordic? 1a) If there is a driver for Linux, can I use it with Embedded Linux or do I have to make some modifications to it? 1b) If there isn't a driver for Linux, can I write my own Embedded
  5. I have a TLP521 driving a set of relays. The circuit is shown below. To switch on the relay, I will need to sink the current to complete the P521 circuit, which will trigger the relay. I am thinking to use a ULN2803A to sink the current as shown in the below diagram. This would mean that when I pull the Qa pin of shift register as HIGH, the 1C point (on ULN2803A) should be zero (grounded) and the circuit should be complete. Is this the correct way to do it? Please note that the common and gnd of ULN2803A are grounded and there is no +Vcc on the IC. Is this OK, or should I connect the
  6. I have a need to connect an ARM micro-controller with 3.3V digital output pins to a few 12V solenoid water valves. I figured that I can use a ULN2803AP for this task. The internal circuit for each input/output is depicted below: Couple of questions: Is the attached schematic correct? Do I need anything else in the circuit to protect the micro-controller? Anything else needed to protect the ULN2803A? And do I tie the +12V and +5V grounds together? The load I'm driving is rated at about 400mA, 100mA shy of what this part is rated for ( each output ). Th
  7. It seems Arduino Due ( 32-bit, 84 Mhz, ARM-Cortex-M3-based SAM3X8E ) was released today. In addition, clearly there is a myriad of processors in this category ( 32-bit / 48-96 Mhz / ARM ) as well as corresponding prototyping boards: NXP LPC1768 / mBed STM32 / Discovery PIC32 / ChipKit PIC32 / Parallax Propeller LM4F120 / TI Launchpad etc. I am trying to understand the appeal of these "in-between" microprocessors, which to me appear to lie in between the low-end AVR/MSP430/etc. (pros: inexpensive, low-power, small-footprint) and the high-end A