Buy an Axon, Axon II, or Axon Mote and build a great robot, while helping to support SoR.
0 Members and 1 Guest are viewing this topic.
I haven't tried myself, but not using it I've heard you can only get a few feet range. With IrDA you can the range of a TV remote.
Using an integrated receiver, 10 m is easily obtainable (range depends on type of receiver, alignment and IR power).After all, remotes use the same scheme and I have gone ~18m once I experimented with IR remote data transfers.With optics, up to around 1.5 km/~1 mile is possible
/************************ * PWM Setup ************************/ setup_ccp1(CCP_PWM); setup_ccp2(CCP_PWM); // Setup Timer 2 for a 4.9 kHz PWM frequency // PWM Period = (1/clock)*4*t2div*(period+1) = (1/20000000)*4*4*(254+1) = 0.204 ms (which is 4.9 kHz) setup_timer_2(T2_DIV_BY_4, 0xFE, 1);
// Set the motor PWM duty cycles // 0 = 0%, 255 = 100% if (left_pwm_pct >= 95) left_pwm_pct = 100; left_pwm_duty = (int)left_pwm_pct * 2.55; set_pwm1_duty(left_pwm_duty); if (right_pwm_pct >= 95) right_pwm_pct = 100; right_pwm_duty = (int)right_pwm_pct * 2.55; set_pwm2_duty(right_pwm_duty);
Inserted into .c file in main(): setup_ccp1(CCP_PWM); set_pwm1_duty(264); setup_comparator(NC_NC_NC_NC); setup_vref(FALSE);
i also already able to use this PWM signal as the carrier signal for my infrared UART transmission at 19.2kBaud. The range that i can achieve is around 7m - 8m and i was using Vishay 455kHz TSOP7000 as the receiver, Vishay TSAL6200 IR LED as the transmiiter. Can anybody explain in detail how to use a MOSFET to boost the range?[...]Any suggestion will be appreciate
I think I know why you are seeing a reduced voltage at the output of your CMOS NOR gate. That CMOS gate does not have enough current sourcing capability to drive your MOSFET gate properly. You need something that has the ability to drive that MOSFET gate at frequency. The MOSFET gate has capacitance, which is why it is loading your NOR gate. Plus, you need to drive that MOSFET at 8V, not 5V, to switch it completely ON. Use an NPN transistor between your NOR gate and the MOSFET to boost voltage and current.
I suggest that you either use a 38kHz IR-receiver, or up the carrier to 455 kHz, since what you do is sort of a dead case - a range of 7..8m is actually quite good with such a huge frequency mismatch.Btw. Where did you get the TSOP700 and at what price? I'd like to find a place cheaper than the $7 that a Danish seller wants (which is utterly out of proportion compared to what I pay for 38kHz receivers).
Now i was half way looking on the datasheet for the ULN2003A darlington array IC, it look like able perform the same function that similar to the combination of the NPN transistor and MOSFET to drive IR LED, so this IC possible to drive an IR LED? Anybody can give me some comment? Since using NPN BJT and MOSFET to drive IR LED is more complicated.
Yup, now i using the TSOP7000 receiver with 455KHz PWN carrier signal, and just can get a range of 7m.The IR reciever i buy it from the internet, www.farnell.com. It is around $5
Started by Maltaeron
Started by shyam4uall
Started by tristantech
Started by joe61