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maelli01

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Everything posted by maelli01

  1. 2018: warming up my old thread ;-) good news: not a single crash in the last 4 months, 24/7 operation. I changed ISP and router box back in September. So I guess the TM4C1294 did not like my old router. With the new Fritzbox 7360 it works like a charm.
  2. it is classic LED multiplexing, rows and columns. I measured around 20mA in total when 3 digits are on, so this is an average current of around 1.2mA per LED (most numbers have around 5-7 segments on). Only one column driver is active high at a time, I go through the four of them with 64 Hz repetition, to avoid flicker. The "1s" are somewhat bright than the "fuller" numbers. For sure I would add resistors (at the segments, not the rows) if using a red or yellow display.
  3. An output power display for my solar system. G2553 Launchpad, Blue 4-digit LED display, RS485 Transceiver SN65HVD12P (a low power, 3.3V version of the standard SN75176), this is all there is. All pins are used, 4 + 7 for the multiplexed LEDs (no resistors: Blue LED, 3.6V supply, output resistance of the pins limit the LED current) 3 pins for UART and send/receive for the SN65. 2 pins for 32768Hz xtal (I had this one soldered in on the LP, so why not use it) The MSP asks the inverter over RS485/Modbus "what is your current output power". After less than half a se
  4. exactly, and the second diode to make it fool-proof
  5. Did anybody been succesful in writing to the SD card on the FR5994? For me the out of the box demo does not work for SD-logging. When re-installing it, no idea whether it worked when originally came out of the box ;-( Is there a "hello world on SD card" example using the fr5994 around somewhere? update: yesterday it did not work and I did not know why today I got it working (the out of the box project) and I do not know why.... ;-)
  6. The example msp430fr5994x_lpm4-5_02.c is supposed to show how little current is used in this mode. In the file it says: // MSP430FR5x9x Demo - Entering and waking up from LPM4.5 via P1.3 interrupt // with SVS disabled // // Description: Download and run the program. When entered LPM4.5, no LEDs // should be on. Use a multimeter to measure current on JP1 and // compare to the datasheet. When a positive voltage is applied // to P1.3 the device should wake up from LPM4.5. This will enable //
  7. Weekend-project: Autoranging microvoltmeter based on the MSP430FR4133 launchpad. ADC used: MIcrochip MCP3422, an 18bit, 3.75 sample/second Sigma Delta with 2 differential inputs. I2C interface This nice little chip contains a programmable amplifier (x2,x4,x8) and a not-too-bad internal reference of 2.048V. Max input range is +/-2.048V, resolution (8x amplified) is 2uV. Hand-etched a single layer PCB which goes on top of Launchpad. Type K cable in hot water: 2.93mV, 73Kelvin temp difference to ambient compare with my Fluke 289, 0.06% (datasheet says 0.05% typical, 0.35
  8. Hioki multimeter MSP430F449 8:12
  9. had this thing now running 24/7 for more than a year. Each time the ethernet library crashed, watchdog would trigger, count up one and restart the board. It crashed 32 times in the last 12 months. ;-) not often, but often enough to be a useless bit of kit. Has the problem been solved in the meantime? I have not been looking around in the forum much, but I have the impression that I am/was not the only one with issues. Could it make sense to upgrade to the latest energia?
  10. In the Horowitz/Hill Art of Electronics, third edition, design practices with discrete 74HCxxx, FPGA and Microprocessor are compared and discussed. As an example, the ultimate gibberish machine is described, a circuit that sends out a succession of pseudorandom bytes, as standard RS232 serial data, with 2 selectable speeds, 9600 / 1200 baud. Independent of the processor type, the implementation with a small micro and program it in C looks like the clear winner here, smallest engineering effort, lowest hardware effort (have to admit that I do not have the faintest idea about FPGA.) Th
  11. it is a long time ago since I hacked this together. For the LNK304 based 15V supply I more or less followed this: https://ac-dc.power.com/design-support/reference-designs/design-examples/der-231-132-w-power-supply/ Adapt R8 and R9 for different output voltage. The UF4007 is a cheap but rather fast diode, a normal 1N4007 will NOT work. I found this LNK chips very easy to use. But yes, these things handle high voltage without potential separation. I always use a separation transformer when experimenting and keep my hands im my pockets...
  12. sure you can power an MSP430 from 2 AA cells. The unequal power drain should be manageable for a hobby project. However, for a "product" it is probably not a too good idea: - what happens when inserting / removing batteries? - 2 cells discharged during months, 2 others not, might be o.k. for alkalines, but for long term using Nimh? I do not know. - The MSP can use the internal reference for battery voltage measurement. You have to check the datasheet whether the 1.5V reference works when 2 cells are at the end of life. - you might also check for wrong polarity. The german clever desig
  13. Last year my daughter (she was almost 7 back then) got interesting in soldering. So I let het solder stuff together, no function whatsoever. It did not last long, until she wanted to solder something that "does something". So I took the challenge and designed this christmas tree. - FR2 board, copper artwork by me, other side by my daughter. (cheap FR2 is better for using felt tip pens.. almost like paper) - G2553, all 16pins to simple LEDs, various colours - simple discrete regulator (another led+ transistor) for more or less 3V - powered by USB - mostly through-hole (soldered by
  14. Bike light follow-up: reverse engineering time! here is my almost complete circuit diagram. IC1 is a voltage regulator: 2.5V, exact type I could not find out. Only the MSP runs on the regulated voltage, all the rest runs from the raw battery voltage. Voltage divider R2 1M / R3 330K measure the battery voltage (some microamps get lost here) LED2 and 3 are indicator (red/green) LED1 is the power led PWM is 20kHz, coming from pin 11 of the MSP. Main switch is a Si4562, N and P channel 20V 5A mosfet. Inductor is 100uH. Instead of using only the upper fet, they alternately
  15. power an msp430 without power pins ;-) http://www.eevblog.com/2015/12/18/eevblog-831-power-a-micro-with-no-power-pin/
  16. Reading this discussion on e2e.ti.com does not give me a good feeling. Seems like nobody wants to solve the problem or even admit there is one :-( meanwhile I added a watchdog (4secs) into my code. I feed the dog after the client.print function calls. The watchdog triggers more often than not. I have the strong feeling that sometimes the client.print(xx); function gets stuck in nowhereland for ever. Not good. With the device resetting every now and then, I cannot log any data.
  17. My high tech, German street legal, bicycle light failed. Corrosion on the battery contacts, one day it worked, the other not. So I cracked the damn thing open. Solid build quality, waterproof, but not built to be repairable. As far as I remember, I bought it back in 2006. So what is inside: An MSP430F1122, doing all the business: - Battery charge termination (four AA NIMH) - Two LED intensity levels PWM - 2 color status led (blink duty cycle would indicate remaining charge) - Pushbutton, long for on/off, short for low/high The electronics still works
  18. converted the watchdog example from Tivaware into Energia. it should explain itself... I tested this with the connected launchpad TM4C1294 5 blinks, resets itself, 5 blinks, on and on.... /* 6.11.2015 Watchdog example */ #define LED RED_LED #include <stdint.h> #include <stdbool.h> #include "driverlib/sysctl.h" #include "driverlib/watchdog.h" unsigned long oldmillis; unsigned int timeout; void setup() { pinMode(LED, OUTPUT); SysCtlPeripheralEnable(SYSCTL_PERIPH_WDOG0); WatchdogReloadSet(WATCHDOG0_BASE,120000000); WatchdogResetEnable(WATC
  19. Hello all I am building a temperature logging web server around a TM4C1294 LP and several "temperature bugs", little sensors built around a MSP430G2553 and I2C temp sensors. The web server is connected with these "bugs" via NRF24 modules. (at the moment only one active) The server logs the temperature data over long time and shows them on a table. Time is synced with NTP once an hour. I am using Energia 16 Everything works fine and as expected However, the whole system is not reliable. The more often I connect via web browser, the more likely it will simply not accept a
  20. Did anybody manage to get the SNTP client (NTP, TIRTOS) working on a EK-TM4C1294XL launchpad? I found this http://software-dl.ti.com/dsps/dsps_public_sw/sdo_sb/targetcontent/ndk/2_24_03_35/exports/ndk_2_24_03_35/docs/doxygen/html/sntp_8h.html and this http://e2e.ti.com/support/embedded/tirtos/f/355/p/430488/1549602 but did not help me much, too confusing for stupid me any suggestioins, working example to learn from?
  21. Problem solved, thanks, tripwire The space in the path was the culprit. Nice little trap that is.... The space wasn't even mine, it was created by Windows....
  22. Hello there I am trying to get the simple example given in Ti Rtos to work. I am using CCS 6.1.0 and TI rtos 2.14.00.10 on a Tiva Connected lauchpad. Installed the Ti-Rtos for Tiva from CCS. Fresh. Windows 8.1 What I get is a compiler error (see below). And it does not build anything. Haven't touched any of the source code of the example files in "PWM Example". anybody any clue? cheers and thanks for any help **** Build of configuration Debug for project pwmled_EK_TM4C1294XL_TI_TivaTM4C1294NCPDT **** "C:\\ti\\ccsv6\\utils\\bin\\gmake" -k all making ../src/sysbio
  23. you might get a lower power solution if you power the whole MSP430 from a regulator and forget about the internal reference. No, not a 7805, rather something like a MCP1700. Draws only 1.6uA. Regulators are not as bad as they used to be.
  24. Thanks RobG! Of course this works now. Stupid me. Strange though, performance wise, this bitbanding does not seem to help any thing, this code, built around the example msp432p401_cs_03, "configuration for 48Mhz". volatile uint32_t i; P1DIR |= BIT0; while (1) { P1OUT |= BIT0; P1OUT &= ~BIT0; BITBAND_PERI(P1OUT,0)=1; BITBAND_PERI(P1OUT,0)=0; for(i=0;i<2;i++); } results in this signal: - first pulse exactly the same time as second one - much slower than I expected: 330nS per pulse, that is 16 clock cycles -
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