Bicycle USB Charger

This circuit has been developed to add a USB charging port to a bicycle for charging a mobile phone. The input supply for the circuit is produced by a dynamo (6V, 3W dynamo) in the bicycle.

The circuit is based on LM2596-5.0. It is a 3A step down voltage regulator. LM 2596 are available in fixed output voltage of 3.3, 5, 12v and an adjustable output version. The LM2596 series operates at a switching frequency of 150 kHz, thus allowing smaller-sized filter components than what would be needed with traditional lower-frequency switching regulators. The IC provides all active functions for a step-down (buck) switching regulator, capable of driving a 3A load with excellent line and load regulation.

Circuit & Part list

  • C1        1000uf
  • C2        470 uf
  • D1-D2        1N5818
  • D5        1N5818
  • J        Dynamo 6v 3W
  • L        33 u
  • LED
  • R          1k
  • SW        1 on/off switch
  • IC        LM2596
  • USB-A Connector

How it Works?

The alternating voltage generated by the dynamo is converted to DC by a full-wave bridge rectifier comprising Schottky barrier rectifier diodes D1 through D4 and a filtering electrolytic capacitor (C1). The output of the bridge rectifier, which is charged to peak value of AC voltage (nearly 10V), is input to switching regulator LM2596-5.0 to provide a regulated 5V (DC) output, which is suitable for charging mobile devices using the USB connector.

The 5mm LED (LED1) in the circuit indicates output status. Feedback connection FB (pin 4 on IC1) is connected directly to output voltage at electrolytic capacitor C2. The 33μH inductor (L1) should be rated for a DC current of at least 1A. The dynamo output is connected to the circuit by switch S1.

What is Omega 2 Board?

Omega 2 board is the development boards from Onion. It comes packed with built-in Wi-Fi and on-board flash storage. You do not have to worry about buying Wi-Fi dongles or installing operating system images onto external SD cards.

Using the Omega2 is just like using a desktop computer. It has built simple and intuitive apps  to interact with the Omega2. It also have an App Store where you can discover even more apps. The Omega2 runs the Linux Embedded Development Environment (LEDE) operating system, a distribution based on OpenWRT.  You can think of the Omega2 as a tiny Linux server with Wi-Fi.

The Omega2 can be easily added to your existing Arduino projects. Another important benefit of running Linux is that the Omega2 can be programmed with whatever language you want.

Omega 2 Specs

Memory64MB Memory
Storage16MB Storage
USBUSB 2.0
MicroSD Slot
No
WiFi adapterb/g/n Wi-Fi
GPIOs15
PWM2
UART2
I2C1
SPI1
I2S1

Pin out

Omega2 Accessories

 

Expansion Docs

The Expansion Dock powers the Omega2, it breaks out all of the GPIOs, and allows you to expand your Omega2 with expansion modules. It has a USB-to-serial chip on-board, allowing you to access the Omega2 easily through the serial terminal.

Mini Dock

The Mini Dock provides power to the Omega2, and it allows you to plug in USB devices

 Power Dock

Arduino Dock

 

 

How to Measure DevOps Success?

How do you measure DevOps success ?

You may not know if you are achieving success with your DevOps implementation unless you measure it and also manage it continuously to keep the key performance indicators (KPI) in right balance.

Following are the few KPIs that help in measure DevOps success.

  • KPI 1 Quality
  • KPI 2 Speed
  • KPI 3  Application Performance
  • KPI 4 Customer experience
  • KPI 5 Business Success

Quality

Underline principle of DevOps is faster and better software delivery.

Shorter development cycles and close collaboration under a DevOps approach mean you catch problems before they go to production, and so spend less time fixing them.

Software quality is directly correlated to customer- impacting issues, so it pays to invest time and energy into addressing quality issues earlier in the cycles. Anyways you do not want customers to be the ones discovering your issues.

Following metrics  can help track and quantify the quality of  your software’s overall continuous improvement efforts:

  • Deployment success/failure  rate
  • Application error rates
  • Issue severity
  • Outstanding bugs

Since many quality issues do not appear until the software hits production, the ability to compare all metrics pre/post deploy is extremely helpful in understanding the impact of a specific release. This approach also allows teams to respond quickly and rollback a release or provide a quick resolution to any incidents that have occurred.

Speed

DevOps teams need to focus on the speed of development, delivery, and response to issues that occur in production. Metrics to consider for helping to track progress and success in this area include:

  • Lead time for changes
  • Frequency of code releases
  • Mean time to resolution

Application Performance

Catching performance problems before they manifest requires tracking number of performance metrics like

  • Up-time (availability)
  • App response time
  • Database response time
  • % of transaction time spent in database
  • Slow SQL queries
  • Resource usage

Customer experience

A poor application performance will result in bad customer experience. Customer experience KPI is directly related to Application performance.  Following are the few metrics that can help measure customer experience.

  • Response time of key transactions
  • Frequency of key transactions
  • Number of visits per user/per week
  • User growth rates
  • Amount of time spent in app

Business Success

Business success can be measured by measuring goals that are important for the company. For example a software can be valuable to the company when it helps grow the customer base, increase revenue, reduce customer service costs,  or some other objectives.

These objectives can be identified by talking to the business stakeholders and understand their business goals and how they will be impacted by delivering the software quickly.

Measure DevOps Success Picture

In a nutshell, all the KPIs are interrelated to each other and impact each other. If we have quality  and or Speed issues on production it will result in bad customer experience which in turn will lead to reduced business success. So, if we measure the 5 KPIs we can find out if our DevOps implementation is resulting in Business success.

KPIMetrics
Quality1. Deployment success/failure rate
2. Application error rates
3. Issue severity
Outstanding bugs
Speed1. Lead time for changes
2. Frequency of code releases
3. Mean time to resolution
Application Performance1. Uptime (availability)
2. App response time
3. Database response time
4. % of transaction time spent in database
5. Slow SQL queries
6. Resource usage
Customer Experience1. Response time of key transactions
2. Frequency of key transactions
3. Number of visits per user/per week
4. User growth rates
Amount of time spent in app
Business SuccessDepending on Business Goals.