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Hello Ondra The simple calculation for the base current of the transistor is collector current/hfe. hfe for the 2N3906 is anywhere between 30 and 300. For your applications the transistors are being used as switches so they can be driven into saturation. Using the hfe figure of 30, the base current ...

Note: A supply voltage below 12v might affect the reliability of the normal high voltage programming operation, and would only be suitable when the LVP (Low Voltage Programming) option was being used.

Sean

Hello, The main input capacitor on the EB006 board is rated at 16v. This is connected across the input voltage after it has passed through a bridge rectifier so an 18v input supply will probably cause it to operate too close to its operating limit (or possibly above). I would recommend some form of ...

Hello Ron, The use of the timer 0 interrupt should not significantly affect any of the other functions if the standard interrupt service rules are observed: Keep the service routines short. Take care when modifying registers and global variables that may be being used in the main program. The macro ...

Hello Joe The C compiler ignores everything between /* and */ characters (they are included in the C-code box to prevent the example text from being compiled). The option_reg assignment is not being compiled or executed in this case. All the sample text should be deleted from a C-code block and the ...

The technique used to create extra PWM channels depends on the frequency and accuracy required. One of the best ways to generate accurate timing intervals is the Timer 0 interrupt. Timer 0 continuously counts from 0 to 255 and can generate an interrupt when it overflows back from 255 to 0. The clock...

Hi Ron, The best way to store single bits of data (or small combinations of bits) is to use the AND, OR and XOR functions in a calculation block. These commands can be used to manipulate individual bits within a byte or integer variable. If you create a variable called Flags: A bit can be set by ORi...

Hello Ron, I/O pins generally remain in the last state they were set. On power-up all I/O pins are configured as inputs (the output buffers are tri-state - both the high and low output drivers are off). In Flowcode they will remain as inputs unless they are accessed by an output command, or an assoc...

Hello Legoman, The ADC component functions: SampleADC, ReadAsInt and ReadAsByte can be included in the macro called by the timer interrupt. The returned value and any control flags can then be saved to global variables. It is advisable not to do too much more from within the interrupt service routin...

Hello Ron, The SampleADC function from the ADC component must be executed before each attempt to read a result. The chip has a single ADC and an analogue multiplexer to connect the selected ANx input to it. Multiple ADC components can be loaded into a flowchart. Each one can be connected to a select...

Hello Ondra The external interrupt pins (INTx) are edge triggered - they react when the signal level changes in the selected direction. The active edge (positive going or negative going) can be selected in the Flowcode interrupt configuration screen. The fast reaction time of interrupts can sometime...

I have been testing the Piklab programmer application (piklab-prog win32 static version) from sourceforge.net. It is currently in beta testing (v0.15.1), has a command line interface that could be made to work with Flowcode, and supports several programmers. Devices were successfully programmed usin...

Hello Nils

Global declarations can be made via the Edit->Supplementary Code menu.

Use the "Definitions and function declarations" window to declare your new variable.

Hello Alan The code you are using should be copied to a custom interrupt component. If you copy an interrupt component into your program, and double-click on it to open the configuration window, you can select 'Custom' in the 'Interrupt on' box. Put a meaningful name in the 'Display name' box, and m...

Here are some examples of the code required for custom interrupts. These simple examples are written for the ATMEGA8, as illustrations of the type of information required for each section of the custom interrupt component. When using alternative devices please refer to the individual device data she...

Hello, Reading a 10-bit A/D conversion is as easy as reading an 8-bit conversion. The double register read, bit shifting and integer assembly is all handled by Flowcode. The variable receiving the conversion value must be declared as an integer and will be set to a value between 0 and 1023. There is...

Hello Wayne, The 16k bytes of Flash memory in the 18F4420 are used 2 bytes at a time due to the 16-bit program word format, resulting in 8k words The 16F877 has 14k bytes of flash that are used 14-bits at a time, giving it the same 8k of program words. Devices with more program memory include the 18...

Hello Ondra, When you read the ADC value as a byte (8-bit conversion), the converter divides the reference voltage (5v) by 256, giving a resolution of approximately 20mV (19.53mV). The value returned by the component is the input voltage divided by the resolution (460mV / 20mV = 23). If you read the...

Hi Koen, The solution to this problem is to modify the flash programming command line in 'tools\MX_bats\avrc.bat'. Adding the -u switch prevents the fuses from being read. Example: :ProgFlash @SET AVRDUDEcmd="%~dp0..\AVRDUDEusb\avrdude.exe" -p %1 -P %3 -c %2 -u -U flash:w:%4 @GOTO Send The -u switch...

Flowcode for AVR now has the ability to program the device fuse settings from the Chip->Configure menu option. The following settings will be used as defaults for all devices: 0x0,0xdf 0x1,0xff 0x2,0xff The first value in each pair selects the fuse to be programmed: 0x0 = Fuse High Byte (hfuse) 0x1 ...

I have carried out some interrupt timing tests using Flowcode and an ATMEGA168 running at 4MHz and 20MHz. Using a simple program to allow the value on PORT B to be incremented by an interrupt on INT0, the following response times were measured: 4MHz xtal - 12us 20MHz xtal - 2us The program continuou...

Support for char, int and other data types is the responsibility of the C compiler, not the target device. The example program (ex 2.4) compiles and runs on an ATMEGA32 with all the variables declared as unsigned char. Do you get compiler warnings/errors when you compile the original program code (u...

Hello First the compiler warning The warning is caused by the line: void main(void) The GCC compiler is capable of generating code that can return an integer value (to a calling function or operating system) on termination. The programs compile without warnings if the line is changed to: int main(vo...