All Blog Posts (53)

I faced several problems while working on the PIC to PC communication portion of the programming. Here are some of the major issues with my solutions:

1. Hyperterminal not found.

It seems like Windows 7 does not come with Hyperterminal software. Pretty simple fix: go to the Dropbox link I attached below and download hypertrm.dll and hypertrm.exe. Double clicking hypertrm.exe should start Hyperterminal. If not, try moving these files into C:\Program Files\Windows NT and…

Few things that took me a while to figure out:

1. When using high and low priority interrupts, GIEH must ALSO be enabled along with GIEL (bits 7 and 6) for low priority interrupts to occur.

2. Even when interrupts are not enabled (such as external interrupts on INT0), these are still being flagged. Thus, if there are multiple sources of interrupts and if the interrupt source checking is not handled carefully, disabled interrupt routines may still occur. For example, in my…

Code given in textbook is something like this:

WR_INS

bcf RS ;clear Register Status bit

movwf temp_lcd ;store instruction

andlw 0xF0 ;mask 4 MSB

movwf LATD ;send 4 MSB

bsf E ;pulse enable high

call delay5ms

swapf temp_lcd, 0 ;swap nibbles (result into WREG)

andlw 0xF0 ;mask 4 LSB

bcf E

movwf LATD ;send 4 LSB

bsf E ;pulse enable high

nop

bcf E

call delay5ms ;allow time for change

return

But this does not…

The final runs and presentation are over. Though the results were not what I had hoped for, I can't help but feel proud of what our team has accomplished this term. 

What I Learned in AER201

1. Never give up. Perseverance is key to success in this course - a lot of challenges and adversity will occur through failed ideas or damaged machines, but sometimes the best solutions are born from the most desperate situations.  

2. Advanced Planning and Organization is…

Next week is the second team eval! I can't believe it is this close.

Today was focussed on working together to get the machine ready for a full run. Wiring was secured in place with electrical tape in order to ensure that it was neat and out of the way of actuating motors, a plexiglass mount was made for the PIC board, the arm was reattached and the right gear was re-epoxyed onto the motor. Also, the problem we were having with the rear-right wheel not touching the ground…

Following the integration and test runs that our group conducted today (http://www.youtube.com/watch?v=t1eQQthAIcE&feature=player_embedded), I brought the robot home and fixed some bugs in the circuit and the code. In my final test run, the robot was able to detect all 7 garbage bins, identify their colours, and store their locations. Some pictures of the final UI were taken and have been uploaded into…

Today was the EngSci open house day, and as we were volunteering to talk about AER201 in the common room we were also able to get a lot accomplished.

Though the wiring had been finished before hand, each wire needed to be tinned and then soldered into its respective spot. Once everything was connected and soldered in place by Mason, and each sensor's connectivity was tested and deemed successful, we loaded Tom's program onto the pic and connected his development board to the sensor…

Yesterday the main goal of the lab session was to finish mounting all of the sensors, wire them up, and get ready to connect everything together. Mason and Tom were finishing up the sensor circuit board and the pic board respectively, and I took the time to mount the IR range sensors to the base and break beam sensors to the upper section of the arm. I also ran wire through the base from the sensor to the approximate spot where the sensor board will be mounted on our robot. I'll have to get…

Today I asked Prof. Emami for the circuit diagram of the RTC module. I was then able to make that circuit and integrate it with the PIC Board and my LCD. For those who would like to make their own RTC module, I have uploaded the circuit diagram in my photo section. Be sure to check it out because it really saves you a lot of time.

Below is a video of the working circuit on protoboard:…

Last week, two programmers Kevin Tan and I worked on the circuits for keypad and LCD. As our groups both use the PIC boards to save money for our circuit and electromech members, we designed and assembled the two circuits and connected them to the PIC. They only require some capacitors, resistors, wires and two IC's. Below is a link to a video documenting the results of our work.

http://youtu.be/eSjynyepa6g

Today was Individual Evaluation 2! Because I was fortunate enough to be evaluated closer to the end, the day in the shop was pretty productive.

After remounting the encoder system with a smaller crossbar and battery mount, it was time to begin integrating the circuits and electromechanical subsystems. Mason set up the fuse and emergency switch on the…

Many milestones were hit this week for our team. On Tuesday, we started the beginning of the long integration process, testing out how Tom's coded pulse width modulation would work through Mason's driver board when connected to the fully mounted (and functional) motors. The results were very promising.

On the electromechanical side specifically, The final structure of the robot is complete. The motors were remounted using steel strapping instead of plumbing fittings, which…

Over the weekend, I have finished writing code for the PWM output that can drive motors at different rates. Since Mason has soldered his driver circuit and Abigail has the mobile base assembled, we decided to integrate the three parts together.

The result turned out to be pretty good: the 12V power source powered the entire circuit which then amplified the PWM signals sent from the PIC. Based on the PWM duty cycles, the two motors span at different speeds.…

Today was pretty standard - went to the soldering seminar, and then hit the shop around 3:00. The day was spent prototyping our arm design.

Our arm is passive - we have no motors or actuators attached to it. The concept is pretty basic - small, light balsa wood strips are mounted to a rotational bearing that is centred in the robot, mounted 45cm up. On the end of the arm, elastic bands are used to both stabilize it (preventing unwanted bouncing etc.) and as the…

I spent quite some time trying to be able to write data to EEPROM, but no matter what I did it wouldn't work. Even when I copied the exact same code the book provides, it didn't do anything. I emailed Prof. Emami about it today and this is his response:

*************

Hi Andrew, the reason why it doesn't write to the EEPROM is that you do not disable the EEPROM write…

Hey does any AER group have two AC to DC power supplies? Our group lost ours so may I please ask you guys to do me a favour, if you ever found out you took two power supplies by accident, would you please return one to me? Thanks in advance and I really appreciate that! ps, I am in Tuesday's tutorial. pps, I am the guy carring a sony DSLR everyday in case you don't know me.

Man, Wednesday section is packed. I don't think I'll go back to Wednesday sessions unless I REALLY need the time... lots of people who didn't have labs must have come also, and the tools were in high demand, along with the workspace.

Today, both motors were successfully mounted to the base. The transmission system is complete! I am very proud of my handiwork, as it took me around 2-3 hours to get the alignment of the gears perfect. The result is worth it though - I'll post a…

Today focussed mostly on the fabrication of the drive base module. I was able to complete the entire base, including the mounting of the motors, however my team decided that a full length chassis bar would be more structurally sound than the current half length, and since this is easy to change and mount to the existing base, we decided to do this. The picture below shows the base sans one motor and the cross support for the arm I started during the last hour - I have to remember to take…

And so the weekend of typing, calculating, planning, shopping, and unfortunately not sleeping comes to a close. The infamous report covers have been found, the proposals printed, and are now no longer our problem.

Though it was possible for me to complete my sections of the proposal in 3 long spurts (Friday from 10-2:30 am, Saturday from 11 - 1pm, 5pm-12:30am, and Sunday 11am-8pm) I would not want to do that again. A good target week to start the final report is probably week…

It's probably too late, but here is a VERY handy web-applet for drawing flow charts:

http://www.lucidchart.com/

It's actually the first result Google finds if you search for "flow chart maker," so anyone who looked for one has likely already found this. But here it is anyways.